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Both you and the speck of dust consist of atoms of matter. So does the ground beneath your feet. In fact, everything you can see and touch is made of matter. The only things that arent matter are forms of energy, such as light and sound. Although forms of energy are not matter, the air and other substances they travel through are. So what is matter? Matter is defined as anything that has mass and volume. Mass is the amount of matter in a substance or object. Mass is commonly measured with a balance. A simple mechanical balance is shown in Figure 3.1. It allows an object to be matched with other objects of known mass. SI units for mass are the kilogram, but for smaller masses grams are often used instead. The more matter an object contains, generally the more it weighs. However, weight is not the same thing as mass. Weight is a measure of the force of gravity pulling on an object. It is measured with a scale, like the kitchen- scale in Figure 3.2. The scale detects how forcefully objects in the pan are being pulled downward by the force of gravity. The SI unit for weight is the newton (N). The common English unit is the pound (lb). With Earths gravity, a mass of 1 kg has a weight of 9.8 N (2.2 lb). Problem Solving Problem: At Earths gravity, what is the weight in newtons of an object with a mass of 10 kg? Solution: At Earths gravity, 1 kg has a weight of 9.8 N. Therefore, 10 kg has a weight of (10 9.8 N) = 98 N. You Try It! Problem: If you have a mass of 50 kg on Earth, what is your weight in newtons? An object with more mass is pulled by gravity with greater force, so mass and weight are closely related. However, the weight of an object can change if the force of gravity changes, even while the mass of the object remains constant. Look at the photo of astronaut Edwin E. Aldrin Jr taken by fellow astronaut Neil Armstrong, the first human to walk on the moon, in Figure 3.3. An astronaut weighed less on the moon than he did on Earth because the moons gravity is weaker than Earths. The astronauts mass, on the other hand, did not change. He still contained the same amount of matter on the moon as he did on Earth. The amount of space matter takes up is its volume. How the volume of matter is measured depends on its state. The volume of liquids is measured with measuring containers. In the kitchen, liquid volume is usually measured with measuring cups or spoons. In the lab, liquid volume is measured with containers such as graduated cylinders. Units in the metric system for liquid volume include liters (L) and milliliters (mL). The volume of gases depends on the volume of their container. Thats because gases expand to fill whatever space is available to them. For example, as you drink water from a bottle, air rushes in to take the place of the water. An "empty" liter bottle actually holds a liter of air. How could you find the volume of air in an "empty" room? The volume of regularly shaped solids can be calculated from their dimensions. For example, the volume of a rectangular solid is the product of its length, width, and height (l w h). For solids that have irregular shapes, the displacement method is used to measure volume. You can see how it works in Figure 3.4 and in the video below. The SI unit for solid volumes is cubic meters (m3 ). However, cubic centimeters (cm3 ) are often used for smaller volume measurements. Matter has many properties. Some are physical properties. Physical properties of matter are properties that can be measured or observed without matter changing to a different substance. For example, whether a given substance normally exists as a solid, liquid, or gas is a physical property. Consider water. It is a liquid at room temperature, but if it freezes and
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All of the following are matter except
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Both you and the speck of dust consist of atoms of matter. So does the ground beneath your feet. In fact, everything you can see and touch is made of matter. The only things that arent matter are forms of energy, such as light and sound. Although forms of energy are not matter, the air and other substances they travel through are. So what is matter? Matter is defined as anything that has mass and volume. Mass is the amount of matter in a substance or object. Mass is commonly measured with a balance. A simple mechanical balance is shown in Figure 3.1. It allows an object to be matched with other objects of known mass. SI units for mass are the kilogram, but for smaller masses grams are often used instead. The more matter an object contains, generally the more it weighs. However, weight is not the same thing as mass. Weight is a measure of the force of gravity pulling on an object. It is measured with a scale, like the kitchen- scale in Figure 3.2. The scale detects how forcefully objects in the pan are being pulled downward by the force of gravity. The SI unit for weight is the newton (N). The common English unit is the pound (lb). With Earths gravity, a mass of 1 kg has a weight of 9.8 N (2.2 lb). Problem Solving Problem: At Earths gravity, what is the weight in newtons of an object with a mass of 10 kg? Solution: At Earths gravity, 1 kg has a weight of 9.8 N. Therefore, 10 kg has a weight of (10 9.8 N) = 98 N. You Try It! Problem: If you have a mass of 50 kg on Earth, what is your weight in newtons? An object with more mass is pulled by gravity with greater force, so mass and weight are closely related. However, the weight of an object can change if the force of gravity changes, even while the mass of the object remains constant. Look at the photo of astronaut Edwin E. Aldrin Jr taken by fellow astronaut Neil Armstrong, the first human to walk on the moon, in Figure 3.3. An astronaut weighed less on the moon than he did on Earth because the moons gravity is weaker than Earths. The astronauts mass, on the other hand, did not change. He still contained the same amount of matter on the moon as he did on Earth. The amount of space matter takes up is its volume. How the volume of matter is measured depends on its state. The volume of liquids is measured with measuring containers. In the kitchen, liquid volume is usually measured with measuring cups or spoons. In the lab, liquid volume is measured with containers such as graduated cylinders. Units in the metric system for liquid volume include liters (L) and milliliters (mL). The volume of gases depends on the volume of their container. Thats because gases expand to fill whatever space is available to them. For example, as you drink water from a bottle, air rushes in to take the place of the water. An "empty" liter bottle actually holds a liter of air. How could you find the volume of air in an "empty" room? The volume of regularly shaped solids can be calculated from their dimensions. For example, the volume of a rectangular solid is the product of its length, width, and height (l w h). For solids that have irregular shapes, the displacement method is used to measure volume. You can see how it works in Figure 3.4 and in the video below. The SI unit for solid volumes is cubic meters (m3 ). However, cubic centimeters (cm3 ) are often used for smaller volume measurements. Matter has many properties. Some are physical properties. Physical properties of matter are properties that can be measured or observed without matter changing to a different substance. For example, whether a given substance normally exists as a solid, liquid, or gas is a physical property. Consider water. It is a liquid at room temperature, but if it freezes and
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Both you and the speck of dust consist of atoms of matter. So does the ground beneath your feet. In fact, everything you can see and touch is made of matter. The only things that arent matter are forms of energy, such as light and sound. Although forms of energy are not matter, the air and other substances they travel through are. So what is matter? Matter is defined as anything that has mass and volume. Mass is the amount of matter in a substance or object. Mass is commonly measured with a balance. A simple mechanical balance is shown in Figure 3.1. It allows an object to be matched with other objects of known mass. SI units for mass are the kilogram, but for smaller masses grams are often used instead. The more matter an object contains, generally the more it weighs. However, weight is not the same thing as mass. Weight is a measure of the force of gravity pulling on an object. It is measured with a scale, like the kitchen- scale in Figure 3.2. The scale detects how forcefully objects in the pan are being pulled downward by the force of gravity. The SI unit for weight is the newton (N). The common English unit is the pound (lb). With Earths gravity, a mass of 1 kg has a weight of 9.8 N (2.2 lb). Problem Solving Problem: At Earths gravity, what is the weight in newtons of an object with a mass of 10 kg? Solution: At Earths gravity, 1 kg has a weight of 9.8 N. Therefore, 10 kg has a weight of (10 9.8 N) = 98 N. You Try It! Problem: If you have a mass of 50 kg on Earth, what is your weight in newtons? An object with more mass is pulled by gravity with greater force, so mass and weight are closely related. However, the weight of an object can change if the force of gravity changes, even while the mass of the object remains constant. Look at the photo of astronaut Edwin E. Aldrin Jr taken by fellow astronaut Neil Armstrong, the first human to walk on the moon, in Figure 3.3. An astronaut weighed less on the moon than he did on Earth because the moons gravity is weaker than Earths. The astronauts mass, on the other hand, did not change. He still contained the same amount of matter on the moon as he did on Earth. The amount of space matter takes up is its volume. How the volume of matter is measured depends on its state. The volume of liquids is measured with measuring containers. In the kitchen, liquid volume is usually measured with measuring cups or spoons. In the lab, liquid volume is measured with containers such as graduated cylinders. Units in the metric system for liquid volume include liters (L) and milliliters (mL). The volume of gases depends on the volume of their container. Thats because gases expand to fill whatever space is available to them. For example, as you drink water from a bottle, air rushes in to take the place of the water. An "empty" liter bottle actually holds a liter of air. How could you find the volume of air in an "empty" room? The volume of regularly shaped solids can be calculated from their dimensions. For example, the volume of a rectangular solid is the product of its length, width, and height (l w h). For solids that have irregular shapes, the displacement method is used to measure volume. You can see how it works in Figure 3.4 and in the video below. The SI unit for solid volumes is cubic meters (m3 ). However, cubic centimeters (cm3 ) are often used for smaller volume measurements. Matter has many properties. Some are physical properties. Physical properties of matter are properties that can be measured or observed without matter changing to a different substance. For example, whether a given substance normally exists as a solid, liquid, or gas is a physical property. Consider water. It is a liquid at room temperature, but if it freezes and
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Both you and the speck of dust consist of atoms of matter. So does the ground beneath your feet. In fact, everything you can see and touch is made of matter. The only things that arent matter are forms of energy, such as light and sound. Although forms of energy are not matter, the air and other substances they travel through are. So what is matter? Matter is defined as anything that has mass and volume. Mass is the amount of matter in a substance or object. Mass is commonly measured with a balance. A simple mechanical balance is shown in Figure 3.1. It allows an object to be matched with other objects of known mass. SI units for mass are the kilogram, but for smaller masses grams are often used instead. The more matter an object contains, generally the more it weighs. However, weight is not the same thing as mass. Weight is a measure of the force of gravity pulling on an object. It is measured with a scale, like the kitchen- scale in Figure 3.2. The scale detects how forcefully objects in the pan are being pulled downward by the force of gravity. The SI unit for weight is the newton (N). The common English unit is the pound (lb). With Earths gravity, a mass of 1 kg has a weight of 9.8 N (2.2 lb). Problem Solving Problem: At Earths gravity, what is the weight in newtons of an object with a mass of 10 kg? Solution: At Earths gravity, 1 kg has a weight of 9.8 N. Therefore, 10 kg has a weight of (10 9.8 N) = 98 N. You Try It! Problem: If you have a mass of 50 kg on Earth, what is your weight in newtons? An object with more mass is pulled by gravity with greater force, so mass and weight are closely related. However, the weight of an object can change if the force of gravity changes, even while the mass of the object remains constant. Look at the photo of astronaut Edwin E. Aldrin Jr taken by fellow astronaut Neil Armstrong, the first human to walk on the moon, in Figure 3.3. An astronaut weighed less on the moon than he did on Earth because the moons gravity is weaker than Earths. The astronauts mass, on the other hand, did not change. He still contained the same amount of matter on the moon as he did on Earth. The amount of space matter takes up is its volume. How the volume of matter is measured depends on its state. The volume of liquids is measured with measuring containers. In the kitchen, liquid volume is usually measured with measuring cups or spoons. In the lab, liquid volume is measured with containers such as graduated cylinders. Units in the metric system for liquid volume include liters (L) and milliliters (mL). The volume of gases depends on the volume of their container. Thats because gases expand to fill whatever space is available to them. For example, as you drink water from a bottle, air rushes in to take the place of the water. An "empty" liter bottle actually holds a liter of air. How could you find the volume of air in an "empty" room? The volume of regularly shaped solids can be calculated from their dimensions. For example, the volume of a rectangular solid is the product of its length, width, and height (l w h). For solids that have irregular shapes, the displacement method is used to measure volume. You can see how it works in Figure 3.4 and in the video below. The SI unit for solid volumes is cubic meters (m3 ). However, cubic centimeters (cm3 ) are often used for smaller volume measurements. Matter has many properties. Some are physical properties. Physical properties of matter are properties that can be measured or observed without matter changing to a different substance. For example, whether a given substance normally exists as a solid, liquid, or gas is a physical property. Consider water. It is a liquid at room temperature, but if it freezes and
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Both you and the speck of dust consist of atoms of matter. So does the ground beneath your feet. In fact, everything you can see and touch is made of matter. The only things that arent matter are forms of energy, such as light and sound. Although forms of energy are not matter, the air and other substances they travel through are. So what is matter? Matter is defined as anything that has mass and volume. Mass is the amount of matter in a substance or object. Mass is commonly measured with a balance. A simple mechanical balance is shown in Figure 3.1. It allows an object to be matched with other objects of known mass. SI units for mass are the kilogram, but for smaller masses grams are often used instead. The more matter an object contains, generally the more it weighs. However, weight is not the same thing as mass. Weight is a measure of the force of gravity pulling on an object. It is measured with a scale, like the kitchen- scale in Figure 3.2. The scale detects how forcefully objects in the pan are being pulled downward by the force of gravity. The SI unit for weight is the newton (N). The common English unit is the pound (lb). With Earths gravity, a mass of 1 kg has a weight of 9.8 N (2.2 lb). Problem Solving Problem: At Earths gravity, what is the weight in newtons of an object with a mass of 10 kg? Solution: At Earths gravity, 1 kg has a weight of 9.8 N. Therefore, 10 kg has a weight of (10 9.8 N) = 98 N. You Try It! Problem: If you have a mass of 50 kg on Earth, what is your weight in newtons? An object with more mass is pulled by gravity with greater force, so mass and weight are closely related. However, the weight of an object can change if the force of gravity changes, even while the mass of the object remains constant. Look at the photo of astronaut Edwin E. Aldrin Jr taken by fellow astronaut Neil Armstrong, the first human to walk on the moon, in Figure 3.3. An astronaut weighed less on the moon than he did on Earth because the moons gravity is weaker than Earths. The astronauts mass, on the other hand, did not change. He still contained the same amount of matter on the moon as he did on Earth. The amount of space matter takes up is its volume. How the volume of matter is measured depends on its state. The volume of liquids is measured with measuring containers. In the kitchen, liquid volume is usually measured with measuring cups or spoons. In the lab, liquid volume is measured with containers such as graduated cylinders. Units in the metric system for liquid volume include liters (L) and milliliters (mL). The volume of gases depends on the volume of their container. Thats because gases expand to fill whatever space is available to them. For example, as you drink water from a bottle, air rushes in to take the place of the water. An "empty" liter bottle actually holds a liter of air. How could you find the volume of air in an "empty" room? The volume of regularly shaped solids can be calculated from their dimensions. For example, the volume of a rectangular solid is the product of its length, width, and height (l w h). For solids that have irregular shapes, the displacement method is used to measure volume. You can see how it works in Figure 3.4 and in the video below. The SI unit for solid volumes is cubic meters (m3 ). However, cubic centimeters (cm3 ) are often used for smaller volume measurements. Matter has many properties. Some are physical properties. Physical properties of matter are properties that can be measured or observed without matter changing to a different substance. For example, whether a given substance normally exists as a solid, liquid, or gas is a physical property. Consider water. It is a liquid at room temperature, but if it freezes and
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Both you and the speck of dust consist of atoms of matter. So does the ground beneath your feet. In fact, everything you can see and touch is made of matter. The only things that arent matter are forms of energy, such as light and sound. Although forms of energy are not matter, the air and other substances they travel through are. So what is matter? Matter is defined as anything that has mass and volume. Mass is the amount of matter in a substance or object. Mass is commonly measured with a balance. A simple mechanical balance is shown in Figure 3.1. It allows an object to be matched with other objects of known mass. SI units for mass are the kilogram, but for smaller masses grams are often used instead. The more matter an object contains, generally the more it weighs. However, weight is not the same thing as mass. Weight is a measure of the force of gravity pulling on an object. It is measured with a scale, like the kitchen- scale in Figure 3.2. The scale detects how forcefully objects in the pan are being pulled downward by the force of gravity. The SI unit for weight is the newton (N). The common English unit is the pound (lb). With Earths gravity, a mass of 1 kg has a weight of 9.8 N (2.2 lb). Problem Solving Problem: At Earths gravity, what is the weight in newtons of an object with a mass of 10 kg? Solution: At Earths gravity, 1 kg has a weight of 9.8 N. Therefore, 10 kg has a weight of (10 9.8 N) = 98 N. You Try It! Problem: If you have a mass of 50 kg on Earth, what is your weight in newtons? An object with more mass is pulled by gravity with greater force, so mass and weight are closely related. However, the weight of an object can change if the force of gravity changes, even while the mass of the object remains constant. Look at the photo of astronaut Edwin E. Aldrin Jr taken by fellow astronaut Neil Armstrong, the first human to walk on the moon, in Figure 3.3. An astronaut weighed less on the moon than he did on Earth because the moons gravity is weaker than Earths. The astronauts mass, on the other hand, did not change. He still contained the same amount of matter on the moon as he did on Earth. The amount of space matter takes up is its volume. How the volume of matter is measured depends on its state. The volume of liquids is measured with measuring containers. In the kitchen, liquid volume is usually measured with measuring cups or spoons. In the lab, liquid volume is measured with containers such as graduated cylinders. Units in the metric system for liquid volume include liters (L) and milliliters (mL). The volume of gases depends on the volume of their container. Thats because gases expand to fill whatever space is available to them. For example, as you drink water from a bottle, air rushes in to take the place of the water. An "empty" liter bottle actually holds a liter of air. How could you find the volume of air in an "empty" room? The volume of regularly shaped solids can be calculated from their dimensions. For example, the volume of a rectangular solid is the product of its length, width, and height (l w h). For solids that have irregular shapes, the displacement method is used to measure volume. You can see how it works in Figure 3.4 and in the video below. The SI unit for solid volumes is cubic meters (m3 ). However, cubic centimeters (cm3 ) are often used for smaller volume measurements. Matter has many properties. Some are physical properties. Physical properties of matter are properties that can be measured or observed without matter changing to a different substance. For example, whether a given substance normally exists as a solid, liquid, or gas is a physical property. Consider water. It is a liquid at room temperature, but if it freezes and
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Mass is measured with a
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Both you and the speck of dust consist of atoms of matter. So does the ground beneath your feet. In fact, everything you can see and touch is made of matter. The only things that arent matter are forms of energy, such as light and sound. Although forms of energy are not matter, the air and other substances they travel through are. So what is matter? Matter is defined as anything that has mass and volume. Mass is the amount of matter in a substance or object. Mass is commonly measured with a balance. A simple mechanical balance is shown in Figure 3.1. It allows an object to be matched with other objects of known mass. SI units for mass are the kilogram, but for smaller masses grams are often used instead. The more matter an object contains, generally the more it weighs. However, weight is not the same thing as mass. Weight is a measure of the force of gravity pulling on an object. It is measured with a scale, like the kitchen- scale in Figure 3.2. The scale detects how forcefully objects in the pan are being pulled downward by the force of gravity. The SI unit for weight is the newton (N). The common English unit is the pound (lb). With Earths gravity, a mass of 1 kg has a weight of 9.8 N (2.2 lb). Problem Solving Problem: At Earths gravity, what is the weight in newtons of an object with a mass of 10 kg? Solution: At Earths gravity, 1 kg has a weight of 9.8 N. Therefore, 10 kg has a weight of (10 9.8 N) = 98 N. You Try It! Problem: If you have a mass of 50 kg on Earth, what is your weight in newtons? An object with more mass is pulled by gravity with greater force, so mass and weight are closely related. However, the weight of an object can change if the force of gravity changes, even while the mass of the object remains constant. Look at the photo of astronaut Edwin E. Aldrin Jr taken by fellow astronaut Neil Armstrong, the first human to walk on the moon, in Figure 3.3. An astronaut weighed less on the moon than he did on Earth because the moons gravity is weaker than Earths. The astronauts mass, on the other hand, did not change. He still contained the same amount of matter on the moon as he did on Earth. The amount of space matter takes up is its volume. How the volume of matter is measured depends on its state. The volume of liquids is measured with measuring containers. In the kitchen, liquid volume is usually measured with measuring cups or spoons. In the lab, liquid volume is measured with containers such as graduated cylinders. Units in the metric system for liquid volume include liters (L) and milliliters (mL). The volume of gases depends on the volume of their container. Thats because gases expand to fill whatever space is available to them. For example, as you drink water from a bottle, air rushes in to take the place of the water. An "empty" liter bottle actually holds a liter of air. How could you find the volume of air in an "empty" room? The volume of regularly shaped solids can be calculated from their dimensions. For example, the volume of a rectangular solid is the product of its length, width, and height (l w h). For solids that have irregular shapes, the displacement method is used to measure volume. You can see how it works in Figure 3.4 and in the video below. The SI unit for solid volumes is cubic meters (m3 ). However, cubic centimeters (cm3 ) are often used for smaller volume measurements. Matter has many properties. Some are physical properties. Physical properties of matter are properties that can be measured or observed without matter changing to a different substance. For example, whether a given substance normally exists as a solid, liquid, or gas is a physical property. Consider water. It is a liquid at room temperature, but if it freezes and
|
What is the SI unit for mass?
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Ponds are small bodies of fresh water that usually have no outlet; ponds are often are fed by underground springs. Like lakes, ponds are bordered by hills or low rises so the water is blocked from flowing directly downhill. Lakes are larger bodies of water. Lakes are usually fresh water, although the Great Salt Lake in Utah is just one exception. Water usually drains out of a lake through a river or a stream and all lakes lose water to evaporation. Lakes form in a variety of different ways: in depressions carved by glaciers, in calderas (Figure 1.1), and along tectonic faults, to name a few. Subglacial lakes are even found below a frozen ice cap. As a result of geologic history and the arrangement of land masses, most lakes are in the Northern Hemisphere. In fact, more than 60% of all the worlds lakes are in Canada most of these lakes were formed by the glaciers that covered most of Canada in the last Ice Age (Figure 1.2). Lakes are not permanent features of a landscape. Some come and go with the seasons, as water levels rise and fall. Over a longer time, lakes disappear when they fill with sediments, if the springs or streams that fill them diminish, (a) Crater Lake in Oregon is in a volcanic caldera. Lakes can also form in volcanic craters and impact craters. (b) The Great Lakes fill depressions eroded as glaciers scraped rock out from the landscape. (c) Lake Baikal, ice coated in winter in this image, formed as water filled up a tectonic faults. Lakes near Yellowknife were carved by glaciers during the last Ice Age. or if their outlets grow because of erosion. When the climate of an area changes, lakes can either expand or shrink (Figure 1.3). Lakes may disappear if precipitation significantly diminishes. Large lakes have tidal systems and currents, and can even affect weather patterns. The Great Lakes in the United States contain 22% of the worlds fresh surface water (Figure 1.1). The largest them, Lake Superior, has a tide that rises and falls several centimeters each day. The Great Lakes are large enough to alter the weather system in Northeastern United States by the lake effect, which is an increase in snow downwind of the relatively warm lakes. The Great Lakes are home to countless species of fish and wildlife. Many lakes are not natural, but are human-made. People dam a stream in a suitable spot and then let the water back up behind it, creating a lake. These lakes are called "reservoirs." Click image to the left or use the URL below. URL:
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a small body of fresh water with no stream draining it.
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Ponds are small bodies of fresh water that usually have no outlet; ponds are often are fed by underground springs. Like lakes, ponds are bordered by hills or low rises so the water is blocked from flowing directly downhill. Lakes are larger bodies of water. Lakes are usually fresh water, although the Great Salt Lake in Utah is just one exception. Water usually drains out of a lake through a river or a stream and all lakes lose water to evaporation. Lakes form in a variety of different ways: in depressions carved by glaciers, in calderas (Figure 1.1), and along tectonic faults, to name a few. Subglacial lakes are even found below a frozen ice cap. As a result of geologic history and the arrangement of land masses, most lakes are in the Northern Hemisphere. In fact, more than 60% of all the worlds lakes are in Canada most of these lakes were formed by the glaciers that covered most of Canada in the last Ice Age (Figure 1.2). Lakes are not permanent features of a landscape. Some come and go with the seasons, as water levels rise and fall. Over a longer time, lakes disappear when they fill with sediments, if the springs or streams that fill them diminish, (a) Crater Lake in Oregon is in a volcanic caldera. Lakes can also form in volcanic craters and impact craters. (b) The Great Lakes fill depressions eroded as glaciers scraped rock out from the landscape. (c) Lake Baikal, ice coated in winter in this image, formed as water filled up a tectonic faults. Lakes near Yellowknife were carved by glaciers during the last Ice Age. or if their outlets grow because of erosion. When the climate of an area changes, lakes can either expand or shrink (Figure 1.3). Lakes may disappear if precipitation significantly diminishes. Large lakes have tidal systems and currents, and can even affect weather patterns. The Great Lakes in the United States contain 22% of the worlds fresh surface water (Figure 1.1). The largest them, Lake Superior, has a tide that rises and falls several centimeters each day. The Great Lakes are large enough to alter the weather system in Northeastern United States by the lake effect, which is an increase in snow downwind of the relatively warm lakes. The Great Lakes are home to countless species of fish and wildlife. Many lakes are not natural, but are human-made. People dam a stream in a suitable spot and then let the water back up behind it, creating a lake. These lakes are called "reservoirs." Click image to the left or use the URL below. URL:
|
which of these is not full of fresh water?
|
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"the great salt lake"
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Radioactivity is the tendency of certain atoms to decay into lighter atoms, a process that emits energy. Radioactivity also provides a way to find the absolute age of a rock. First, we need to know about radioactive decay. Some isotopes are radioactive; radioactive isotopes are unstable and spontaneously change by gaining or losing particles. Two types of radioactive decay are relevant to dating Earth materials (Table 1.1): Particle Alpha Composition 2 protons, 2 neutrons Beta 1 electron Effect on Nucleus The nucleus contains two fewer protons and two fewer neutrons. One neutron decays to form a pro- ton and an electron. The electron is emitted. The radioactive decay of a parent isotope (the original element) leads to the formation of stable daughter product, also known as daughter isotope. As time passes, the number of parent isotopes decreases and the number of daughter isotopes increases (Figure 1.1). Radioactive materials decay at known rates, measured as a unit called half-life. The half-life of a radioactive substance is the amount of time it takes for half of the parent atoms to decay. This is how the material decays over time (see Table 1.2). No. of half lives passed 0 1 2 3 4 5 6 7 8 Percent parent remaining 100 50 25 12.5 6.25 3.125 1.563 0.781 0.391 Percent daughter produced 0 50 75 87.5 93.75 96.875 98.437 99.219 99.609 Pretend you find a rock with 3.125% parent atoms and 96.875% daughter atoms. How many half lives have passed? If the half-life of the parent isotope is 1 year, then how old is the rock? The decay of radioactive materials can be shown with a graph (Figure 1.2). Notice how it doesnt take too many half lives before there is very little parent remaining and most of the isotopes are daughter isotopes. This limits how many half lives can pass before a radioactive element is no longer useful for Decay of an imaginary radioactive sub- stance with a half-life of one year. dating materials. Fortunately, different isotopes have very different half lives. Click image to the left or use the URL below. URL:
|
radioactive decay of an isotope leads to the formation of a ____________ product.
|
[
"stable daughter"
] |
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Radioactivity is the tendency of certain atoms to decay into lighter atoms, a process that emits energy. Radioactivity also provides a way to find the absolute age of a rock. First, we need to know about radioactive decay. Some isotopes are radioactive; radioactive isotopes are unstable and spontaneously change by gaining or losing particles. Two types of radioactive decay are relevant to dating Earth materials (Table 1.1): Particle Alpha Composition 2 protons, 2 neutrons Beta 1 electron Effect on Nucleus The nucleus contains two fewer protons and two fewer neutrons. One neutron decays to form a pro- ton and an electron. The electron is emitted. The radioactive decay of a parent isotope (the original element) leads to the formation of stable daughter product, also known as daughter isotope. As time passes, the number of parent isotopes decreases and the number of daughter isotopes increases (Figure 1.1). Radioactive materials decay at known rates, measured as a unit called half-life. The half-life of a radioactive substance is the amount of time it takes for half of the parent atoms to decay. This is how the material decays over time (see Table 1.2). No. of half lives passed 0 1 2 3 4 5 6 7 8 Percent parent remaining 100 50 25 12.5 6.25 3.125 1.563 0.781 0.391 Percent daughter produced 0 50 75 87.5 93.75 96.875 98.437 99.219 99.609 Pretend you find a rock with 3.125% parent atoms and 96.875% daughter atoms. How many half lives have passed? If the half-life of the parent isotope is 1 year, then how old is the rock? The decay of radioactive materials can be shown with a graph (Figure 1.2). Notice how it doesnt take too many half lives before there is very little parent remaining and most of the isotopes are daughter isotopes. This limits how many half lives can pass before a radioactive element is no longer useful for Decay of an imaginary radioactive sub- stance with a half-life of one year. dating materials. Fortunately, different isotopes have very different half lives. Click image to the left or use the URL below. URL:
|
if two half-lives have passed, this percent of the parent isotope remains.
|
[
"25%"
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c7d3f6c6cb0a42a8b7df118a9d1724bb
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Radioactivity is the tendency of certain atoms to decay into lighter atoms, a process that emits energy. Radioactivity also provides a way to find the absolute age of a rock. First, we need to know about radioactive decay. Some isotopes are radioactive; radioactive isotopes are unstable and spontaneously change by gaining or losing particles. Two types of radioactive decay are relevant to dating Earth materials (Table 1.1): Particle Alpha Composition 2 protons, 2 neutrons Beta 1 electron Effect on Nucleus The nucleus contains two fewer protons and two fewer neutrons. One neutron decays to form a pro- ton and an electron. The electron is emitted. The radioactive decay of a parent isotope (the original element) leads to the formation of stable daughter product, also known as daughter isotope. As time passes, the number of parent isotopes decreases and the number of daughter isotopes increases (Figure 1.1). Radioactive materials decay at known rates, measured as a unit called half-life. The half-life of a radioactive substance is the amount of time it takes for half of the parent atoms to decay. This is how the material decays over time (see Table 1.2). No. of half lives passed 0 1 2 3 4 5 6 7 8 Percent parent remaining 100 50 25 12.5 6.25 3.125 1.563 0.781 0.391 Percent daughter produced 0 50 75 87.5 93.75 96.875 98.437 99.219 99.609 Pretend you find a rock with 3.125% parent atoms and 96.875% daughter atoms. How many half lives have passed? If the half-life of the parent isotope is 1 year, then how old is the rock? The decay of radioactive materials can be shown with a graph (Figure 1.2). Notice how it doesnt take too many half lives before there is very little parent remaining and most of the isotopes are daughter isotopes. This limits how many half lives can pass before a radioactive element is no longer useful for Decay of an imaginary radioactive sub- stance with a half-life of one year. dating materials. Fortunately, different isotopes have very different half lives. Click image to the left or use the URL below. URL:
|
if 75% of the daughter is produced, this many half-lives have passed.
|
[
"2"
] |
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DNA contains the instructions to create proteins, but it does not make proteins itself. DNA is located in the nucleus, which it never leaves, while proteins are made on ribosomes in the cytoplasm. So DNA needs a messenger to bring its instructions to a ribosome located outside of the nucleus. DNA sends out a message, in the form of RNA (ribonucleic acid), describing how to make the protein. There are three types of RNA directly involved in protein synthesis: Messenger RNA ( mRNA) carries the instructions from the nucleus to the cytoplasm. mRNA is produced in the nucleus, as are all RNAs. The other two forms of RNA, ribosomal RNA ( rRNA) and transfer RNA ( tRNA), are involved in the process of ordering the amino acids to make the protein. rRNA becomes part of the ribosome, which is the site of protein synthesis, and tRNA brings an amino acid to the ribosome so it can be added to a growing chain during protein synthesis. There are numerous tRNAs, as each tRNA is specific for an amino acid. The amino acid actually attaches to the tRNA during this process. More about RNAs will be discussed during the Transcription and Translation Concepts. All three RNAs are nucleic acids, made of nucleotides, similar to DNA ( Figure 1.1). The RNA nucleotide is different from the DNA nucleotide in the following ways: RNA contains a different kind of sugar, called ribose. In RNA, the base uracil (U) replaces the thymine (T) found in DNA. RNA is a single strand molecule. A comparison of DNA and RNA, with the bases of each shown. Notice that in RNA, uracil replaces thymine.
|
which rna brings amino acids to the ribosome?
|
[
"trna"
] |
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DNA contains the instructions to create proteins, but it does not make proteins itself. DNA is located in the nucleus, which it never leaves, while proteins are made on ribosomes in the cytoplasm. So DNA needs a messenger to bring its instructions to a ribosome located outside of the nucleus. DNA sends out a message, in the form of RNA (ribonucleic acid), describing how to make the protein. There are three types of RNA directly involved in protein synthesis: Messenger RNA ( mRNA) carries the instructions from the nucleus to the cytoplasm. mRNA is produced in the nucleus, as are all RNAs. The other two forms of RNA, ribosomal RNA ( rRNA) and transfer RNA ( tRNA), are involved in the process of ordering the amino acids to make the protein. rRNA becomes part of the ribosome, which is the site of protein synthesis, and tRNA brings an amino acid to the ribosome so it can be added to a growing chain during protein synthesis. There are numerous tRNAs, as each tRNA is specific for an amino acid. The amino acid actually attaches to the tRNA during this process. More about RNAs will be discussed during the Transcription and Translation Concepts. All three RNAs are nucleic acids, made of nucleotides, similar to DNA ( Figure 1.1). The RNA nucleotide is different from the DNA nucleotide in the following ways: RNA contains a different kind of sugar, called ribose. In RNA, the base uracil (U) replaces the thymine (T) found in DNA. RNA is a single strand molecule. A comparison of DNA and RNA, with the bases of each shown. Notice that in RNA, uracil replaces thymine.
|
which rna carries information from the nucleus to the cytoplasm?
|
[
"mrna"
] |
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Jupiter is enormous, the largest object in the solar system besides the Sun. Although Jupiter is over 1,300 times Earths volume, it has only 318 times the mass of Earth. Like the other gas giants, it is much less dense than Earth. Because Jupiter is so large, it reflects a lot of sunlight. Jupiter is extremely bright in the night sky; only the Moon and Venus are brighter (Figure 1.1). This brightness is all the more impressive because Jupiter is quite far from the Earth 5.20 AUs away. It takes Jupiter about 12 Earth years to orbit once around the Sun. Astronauts trying to land a spaceship on the surface of Jupiter would find that there is no solid surface at all! Jupiter is made mostly of hydrogen, with some helium, and small amounts of other elements (Figure 1.2). Jupiters atmosphere is composed of hydrogen and helium. Deeper within the planet, pressure compresses the gases into a liquid. Some evidence suggests that Jupiter may have a small rocky core of heavier elements at its center. This image of Jupiter was taken by Voy- ager 2 in 1979. The colors were later enhanced to bring out more details. The upper layer of Jupiters atmosphere contains clouds of ammonia (NH3 ) in bands of different colors. These bands rotate around the planet, but also swirl around in turbulent storms. The Great Red Spot (Figure 1.3) is an enormous, oval-shaped storm found south of Jupiters equator. This storm is more than three times as wide as the entire Earth. Clouds in the storm rotate in a counterclockwise direction, making one complete turn every six days or so. The Great Red Spot has been on Jupiter for at least 300 years, since astronomers could first see the storm through telescopes. Do you think the Great Red Spot is a permanent feature on Jupiter? How could you know? This image of Jupiters Great Red Spot (upper right of image) was taken by the Voyager 1 spacecraft. The white storm just below the Great Red Spot is about the same diameter as Earth. Jupiter has a very large number of moons 63 have been discovered so far. Four are big enough and bright enough to be seen from Earth, using no more than a pair of binoculars. These moons Io, Europa, Ganymede, and Callisto were first discovered by Galileo in 1610, so they are sometimes referred to as the Galilean moons (Figure 1.4). The Galilean moons are larger than the dwarf planets Pluto, Ceres, and Eris. Ganymede is not only the biggest moon in the solar system; it is even larger than the planet Mercury! Scientists are particularly interested in Europa because it may be a place to find extraterrestrial life. What features might make a satellite so far from the Sun a candidate for life? Although the surface of Europa is a smooth layer of ice, there is evidence that there is an ocean of liquid water underneath (Figure 1.5). Europa also has a continual source of energy it is heated as it is stretched and squashed by tidal forces from Jupiter. Numerous missions have been planned to explore Europa, including plans to drill through the ice and send a probe into the ocean. However, no such mission has yet been attempted. In 1979, two spacecraft Voyager 1 and Voyager 2 visited Jupiter and its moons. Photos from the Voyager missions showed that Jupiter has a ring system. This ring system is very faint, so it is difficult to observe from Earth. This composite image shows the four Galilean moons and their sizes relative to the Great Red Spot. From top to bottom, the moons are Io, Europa, Ganymede, and Callisto. Jupiters Great Red Spot is in the background. Sizes are to scale. Click image to the left or use the URL below. URL:
|
which is the nearest of the gas giant planets to the sun?
|
[
"jupiter"
] |
fb39cefcdcdf4c1a975c700d11b83943
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Ice is an example of solid matter. A solid is matter that has a fixed volume and a fixed shape. Figure 4.3 shows examples of matter that are usually solids under Earth conditions. In the figure, salt and cellulose are examples of crystalline solids. The particles of crystalline solids are arranged in a regular repeating pattern. The steaks and candle wax are examples of amorphous ("shapeless") solids. Their particles have no definite pattern. Ocean water is an example of a liquid. A liquid is matter that has a fixed volume but not a fixed shape. Instead, a liquid takes the shape of its container. If the volume of a liquid is less than the volume of its container, the top surface will be exposed to the air, like the oil in the bottles in Figure 4.4. Two interesting properties of liquids are surface tension and viscosity. Surface tension is a force that pulls particles at the exposed surface of a liquid toward other liquid particles. Surface tension explains why water forms droplets, like those in Figure 4.5. Viscosity is a liquids resistance to flowing. Thicker liquids are more viscous than thinner liquids. For example, the honey in Figure 4.5 is more viscous than the vinegar. You can learn more about surface tension and viscosity at these URLs: http://io9.com/5668221/an-experiment-with-soap-water-pepper-and-surface-tension http://chemed.chem.wisc.edu/chempaths/GenChem-Textbook/Viscosity-840.html (1:40) MEDIA Click image to the left or use the URL below. URL: Water vapor is an example of a gas. A gas is matter that has neither a fixed volume nor a fixed shape. Instead, a gas takes both the volume and the shape of its container. It spreads out to take up all available space. You can see an example in Figure 4.6. Youre probably less familiar with plasmas than with solids, liquids, and gases. Yet, most of the universe consists of plasma. Plasma is a state of matter that resembles a gas but has certain properties that a gas does not have. Like a gas, plasma lacks a fixed volume and shape. Unlike a gas, plasma can conduct electricity and respond to magnetism. Thats because plasma contains charged particles called ions. This gives plasma other interesting properties. For example, it glows with light. Where can you find plasmas? Two examples are shown in Figure 4.7. The sun and other stars consist of plasma. Plasmas are also found naturally in lightning and the polar auroras (northern and southern lights). Artificial plasmas are found in fluorescent lights, plasma TV screens, and plasma balls like the one that opened this chapter. You can learn more about plasmas at this URL: (2:58). MEDIA Click image to the left or use the URL below. URL: Why do different states of matter have different properties? Its because of differences in energy at the level of atoms and molecules, the tiny particles that make up matter. Energy is defined as the ability to cause changes in matter. You can change energy from one form to another when you lift your arm or take a step. In each case, energy is used to move matter you. The energy of moving matter is called kinetic energy. The particles that make up matter are also constantly moving. They have kinetic energy. The theory that all matter consists of constantly moving particles is called the kinetic theory of matter. You can learn more about it at the URL below. Particles of matter of the same substance, such as the same element, are attracted to one another. The force of attraction tends to pull the particles closer together. The particles need a lot of kinetic energy to overcome the force of attraction and move apart. Its like a tug of war between opposing forces. The kinetic energy of individual particles is on one side, and the force of attraction between different particles is on the other side. The outcome of the "war" depends on the state of matter. This is illustrated in Figure 4.8 and in the animation at this URL: http://w In solids, particles dont have enough kinetic energy to overcome the force of attraction between them. The particles are packed closely together and cannot move around. All they can do
|
state of matter that lacks a fixed volume and a fixed shape
|
[
"gas"
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Ice is an example of solid matter. A solid is matter that has a fixed volume and a fixed shape. Figure 4.3 shows examples of matter that are usually solids under Earth conditions. In the figure, salt and cellulose are examples of crystalline solids. The particles of crystalline solids are arranged in a regular repeating pattern. The steaks and candle wax are examples of amorphous ("shapeless") solids. Their particles have no definite pattern. Ocean water is an example of a liquid. A liquid is matter that has a fixed volume but not a fixed shape. Instead, a liquid takes the shape of its container. If the volume of a liquid is less than the volume of its container, the top surface will be exposed to the air, like the oil in the bottles in Figure 4.4. Two interesting properties of liquids are surface tension and viscosity. Surface tension is a force that pulls particles at the exposed surface of a liquid toward other liquid particles. Surface tension explains why water forms droplets, like those in Figure 4.5. Viscosity is a liquids resistance to flowing. Thicker liquids are more viscous than thinner liquids. For example, the honey in Figure 4.5 is more viscous than the vinegar. You can learn more about surface tension and viscosity at these URLs: http://io9.com/5668221/an-experiment-with-soap-water-pepper-and-surface-tension http://chemed.chem.wisc.edu/chempaths/GenChem-Textbook/Viscosity-840.html (1:40) MEDIA Click image to the left or use the URL below. URL: Water vapor is an example of a gas. A gas is matter that has neither a fixed volume nor a fixed shape. Instead, a gas takes both the volume and the shape of its container. It spreads out to take up all available space. You can see an example in Figure 4.6. Youre probably less familiar with plasmas than with solids, liquids, and gases. Yet, most of the universe consists of plasma. Plasma is a state of matter that resembles a gas but has certain properties that a gas does not have. Like a gas, plasma lacks a fixed volume and shape. Unlike a gas, plasma can conduct electricity and respond to magnetism. Thats because plasma contains charged particles called ions. This gives plasma other interesting properties. For example, it glows with light. Where can you find plasmas? Two examples are shown in Figure 4.7. The sun and other stars consist of plasma. Plasmas are also found naturally in lightning and the polar auroras (northern and southern lights). Artificial plasmas are found in fluorescent lights, plasma TV screens, and plasma balls like the one that opened this chapter. You can learn more about plasmas at this URL: (2:58). MEDIA Click image to the left or use the URL below. URL: Why do different states of matter have different properties? Its because of differences in energy at the level of atoms and molecules, the tiny particles that make up matter. Energy is defined as the ability to cause changes in matter. You can change energy from one form to another when you lift your arm or take a step. In each case, energy is used to move matter you. The energy of moving matter is called kinetic energy. The particles that make up matter are also constantly moving. They have kinetic energy. The theory that all matter consists of constantly moving particles is called the kinetic theory of matter. You can learn more about it at the URL below. Particles of matter of the same substance, such as the same element, are attracted to one another. The force of attraction tends to pull the particles closer together. The particles need a lot of kinetic energy to overcome the force of attraction and move apart. Its like a tug of war between opposing forces. The kinetic energy of individual particles is on one side, and the force of attraction between different particles is on the other side. The outcome of the "war" depends on the state of matter. This is illustrated in Figure 4.8 and in the animation at this URL: http://w In solids, particles dont have enough kinetic energy to overcome the force of attraction between them. The particles are packed closely together and cannot move around. All they can do
|
In which state does most of the matter in the universe occur?
|
[
"plasma"
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Ice is an example of solid matter. A solid is matter that has a fixed volume and a fixed shape. Figure 4.3 shows examples of matter that are usually solids under Earth conditions. In the figure, salt and cellulose are examples of crystalline solids. The particles of crystalline solids are arranged in a regular repeating pattern. The steaks and candle wax are examples of amorphous ("shapeless") solids. Their particles have no definite pattern. Ocean water is an example of a liquid. A liquid is matter that has a fixed volume but not a fixed shape. Instead, a liquid takes the shape of its container. If the volume of a liquid is less than the volume of its container, the top surface will be exposed to the air, like the oil in the bottles in Figure 4.4. Two interesting properties of liquids are surface tension and viscosity. Surface tension is a force that pulls particles at the exposed surface of a liquid toward other liquid particles. Surface tension explains why water forms droplets, like those in Figure 4.5. Viscosity is a liquids resistance to flowing. Thicker liquids are more viscous than thinner liquids. For example, the honey in Figure 4.5 is more viscous than the vinegar. You can learn more about surface tension and viscosity at these URLs: http://io9.com/5668221/an-experiment-with-soap-water-pepper-and-surface-tension http://chemed.chem.wisc.edu/chempaths/GenChem-Textbook/Viscosity-840.html (1:40) MEDIA Click image to the left or use the URL below. URL: Water vapor is an example of a gas. A gas is matter that has neither a fixed volume nor a fixed shape. Instead, a gas takes both the volume and the shape of its container. It spreads out to take up all available space. You can see an example in Figure 4.6. Youre probably less familiar with plasmas than with solids, liquids, and gases. Yet, most of the universe consists of plasma. Plasma is a state of matter that resembles a gas but has certain properties that a gas does not have. Like a gas, plasma lacks a fixed volume and shape. Unlike a gas, plasma can conduct electricity and respond to magnetism. Thats because plasma contains charged particles called ions. This gives plasma other interesting properties. For example, it glows with light. Where can you find plasmas? Two examples are shown in Figure 4.7. The sun and other stars consist of plasma. Plasmas are also found naturally in lightning and the polar auroras (northern and southern lights). Artificial plasmas are found in fluorescent lights, plasma TV screens, and plasma balls like the one that opened this chapter. You can learn more about plasmas at this URL: (2:58). MEDIA Click image to the left or use the URL below. URL: Why do different states of matter have different properties? Its because of differences in energy at the level of atoms and molecules, the tiny particles that make up matter. Energy is defined as the ability to cause changes in matter. You can change energy from one form to another when you lift your arm or take a step. In each case, energy is used to move matter you. The energy of moving matter is called kinetic energy. The particles that make up matter are also constantly moving. They have kinetic energy. The theory that all matter consists of constantly moving particles is called the kinetic theory of matter. You can learn more about it at the URL below. Particles of matter of the same substance, such as the same element, are attracted to one another. The force of attraction tends to pull the particles closer together. The particles need a lot of kinetic energy to overcome the force of attraction and move apart. Its like a tug of war between opposing forces. The kinetic energy of individual particles is on one side, and the force of attraction between different particles is on the other side. The outcome of the "war" depends on the state of matter. This is illustrated in Figure 4.8 and in the animation at this URL: http://w In solids, particles dont have enough kinetic energy to overcome the force of attraction between them. The particles are packed closely together and cannot move around. All they can do
|
state of matter with a fixed volume and a fixed shape
|
[
"solid"
] |
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Ice is an example of solid matter. A solid is matter that has a fixed volume and a fixed shape. Figure 4.3 shows examples of matter that are usually solids under Earth conditions. In the figure, salt and cellulose are examples of crystalline solids. The particles of crystalline solids are arranged in a regular repeating pattern. The steaks and candle wax are examples of amorphous ("shapeless") solids. Their particles have no definite pattern. Ocean water is an example of a liquid. A liquid is matter that has a fixed volume but not a fixed shape. Instead, a liquid takes the shape of its container. If the volume of a liquid is less than the volume of its container, the top surface will be exposed to the air, like the oil in the bottles in Figure 4.4. Two interesting properties of liquids are surface tension and viscosity. Surface tension is a force that pulls particles at the exposed surface of a liquid toward other liquid particles. Surface tension explains why water forms droplets, like those in Figure 4.5. Viscosity is a liquids resistance to flowing. Thicker liquids are more viscous than thinner liquids. For example, the honey in Figure 4.5 is more viscous than the vinegar. You can learn more about surface tension and viscosity at these URLs: http://io9.com/5668221/an-experiment-with-soap-water-pepper-and-surface-tension http://chemed.chem.wisc.edu/chempaths/GenChem-Textbook/Viscosity-840.html (1:40) MEDIA Click image to the left or use the URL below. URL: Water vapor is an example of a gas. A gas is matter that has neither a fixed volume nor a fixed shape. Instead, a gas takes both the volume and the shape of its container. It spreads out to take up all available space. You can see an example in Figure 4.6. Youre probably less familiar with plasmas than with solids, liquids, and gases. Yet, most of the universe consists of plasma. Plasma is a state of matter that resembles a gas but has certain properties that a gas does not have. Like a gas, plasma lacks a fixed volume and shape. Unlike a gas, plasma can conduct electricity and respond to magnetism. Thats because plasma contains charged particles called ions. This gives plasma other interesting properties. For example, it glows with light. Where can you find plasmas? Two examples are shown in Figure 4.7. The sun and other stars consist of plasma. Plasmas are also found naturally in lightning and the polar auroras (northern and southern lights). Artificial plasmas are found in fluorescent lights, plasma TV screens, and plasma balls like the one that opened this chapter. You can learn more about plasmas at this URL: (2:58). MEDIA Click image to the left or use the URL below. URL: Why do different states of matter have different properties? Its because of differences in energy at the level of atoms and molecules, the tiny particles that make up matter. Energy is defined as the ability to cause changes in matter. You can change energy from one form to another when you lift your arm or take a step. In each case, energy is used to move matter you. The energy of moving matter is called kinetic energy. The particles that make up matter are also constantly moving. They have kinetic energy. The theory that all matter consists of constantly moving particles is called the kinetic theory of matter. You can learn more about it at the URL below. Particles of matter of the same substance, such as the same element, are attracted to one another. The force of attraction tends to pull the particles closer together. The particles need a lot of kinetic energy to overcome the force of attraction and move apart. Its like a tug of war between opposing forces. The kinetic energy of individual particles is on one side, and the force of attraction between different particles is on the other side. The outcome of the "war" depends on the state of matter. This is illustrated in Figure 4.8 and in the animation at this URL: http://w In solids, particles dont have enough kinetic energy to overcome the force of attraction between them. The particles are packed closely together and cannot move around. All they can do
|
energy that moves matter
|
[
"kinetic energy"
] |
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Ice is an example of solid matter. A solid is matter that has a fixed volume and a fixed shape. Figure 4.3 shows examples of matter that are usually solids under Earth conditions. In the figure, salt and cellulose are examples of crystalline solids. The particles of crystalline solids are arranged in a regular repeating pattern. The steaks and candle wax are examples of amorphous ("shapeless") solids. Their particles have no definite pattern. Ocean water is an example of a liquid. A liquid is matter that has a fixed volume but not a fixed shape. Instead, a liquid takes the shape of its container. If the volume of a liquid is less than the volume of its container, the top surface will be exposed to the air, like the oil in the bottles in Figure 4.4. Two interesting properties of liquids are surface tension and viscosity. Surface tension is a force that pulls particles at the exposed surface of a liquid toward other liquid particles. Surface tension explains why water forms droplets, like those in Figure 4.5. Viscosity is a liquids resistance to flowing. Thicker liquids are more viscous than thinner liquids. For example, the honey in Figure 4.5 is more viscous than the vinegar. You can learn more about surface tension and viscosity at these URLs: http://io9.com/5668221/an-experiment-with-soap-water-pepper-and-surface-tension http://chemed.chem.wisc.edu/chempaths/GenChem-Textbook/Viscosity-840.html (1:40) MEDIA Click image to the left or use the URL below. URL: Water vapor is an example of a gas. A gas is matter that has neither a fixed volume nor a fixed shape. Instead, a gas takes both the volume and the shape of its container. It spreads out to take up all available space. You can see an example in Figure 4.6. Youre probably less familiar with plasmas than with solids, liquids, and gases. Yet, most of the universe consists of plasma. Plasma is a state of matter that resembles a gas but has certain properties that a gas does not have. Like a gas, plasma lacks a fixed volume and shape. Unlike a gas, plasma can conduct electricity and respond to magnetism. Thats because plasma contains charged particles called ions. This gives plasma other interesting properties. For example, it glows with light. Where can you find plasmas? Two examples are shown in Figure 4.7. The sun and other stars consist of plasma. Plasmas are also found naturally in lightning and the polar auroras (northern and southern lights). Artificial plasmas are found in fluorescent lights, plasma TV screens, and plasma balls like the one that opened this chapter. You can learn more about plasmas at this URL: (2:58). MEDIA Click image to the left or use the URL below. URL: Why do different states of matter have different properties? Its because of differences in energy at the level of atoms and molecules, the tiny particles that make up matter. Energy is defined as the ability to cause changes in matter. You can change energy from one form to another when you lift your arm or take a step. In each case, energy is used to move matter you. The energy of moving matter is called kinetic energy. The particles that make up matter are also constantly moving. They have kinetic energy. The theory that all matter consists of constantly moving particles is called the kinetic theory of matter. You can learn more about it at the URL below. Particles of matter of the same substance, such as the same element, are attracted to one another. The force of attraction tends to pull the particles closer together. The particles need a lot of kinetic energy to overcome the force of attraction and move apart. Its like a tug of war between opposing forces. The kinetic energy of individual particles is on one side, and the force of attraction between different particles is on the other side. The outcome of the "war" depends on the state of matter. This is illustrated in Figure 4.8 and in the animation at this URL: http://w In solids, particles dont have enough kinetic energy to overcome the force of attraction between them. The particles are packed closely together and cannot move around. All they can do
|
Honey pours more slowly than vinegar because honey has greater
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Ice is an example of solid matter. A solid is matter that has a fixed volume and a fixed shape. Figure 4.3 shows examples of matter that are usually solids under Earth conditions. In the figure, salt and cellulose are examples of crystalline solids. The particles of crystalline solids are arranged in a regular repeating pattern. The steaks and candle wax are examples of amorphous ("shapeless") solids. Their particles have no definite pattern. Ocean water is an example of a liquid. A liquid is matter that has a fixed volume but not a fixed shape. Instead, a liquid takes the shape of its container. If the volume of a liquid is less than the volume of its container, the top surface will be exposed to the air, like the oil in the bottles in Figure 4.4. Two interesting properties of liquids are surface tension and viscosity. Surface tension is a force that pulls particles at the exposed surface of a liquid toward other liquid particles. Surface tension explains why water forms droplets, like those in Figure 4.5. Viscosity is a liquids resistance to flowing. Thicker liquids are more viscous than thinner liquids. For example, the honey in Figure 4.5 is more viscous than the vinegar. You can learn more about surface tension and viscosity at these URLs: http://io9.com/5668221/an-experiment-with-soap-water-pepper-and-surface-tension http://chemed.chem.wisc.edu/chempaths/GenChem-Textbook/Viscosity-840.html (1:40) MEDIA Click image to the left or use the URL below. URL: Water vapor is an example of a gas. A gas is matter that has neither a fixed volume nor a fixed shape. Instead, a gas takes both the volume and the shape of its container. It spreads out to take up all available space. You can see an example in Figure 4.6. Youre probably less familiar with plasmas than with solids, liquids, and gases. Yet, most of the universe consists of plasma. Plasma is a state of matter that resembles a gas but has certain properties that a gas does not have. Like a gas, plasma lacks a fixed volume and shape. Unlike a gas, plasma can conduct electricity and respond to magnetism. Thats because plasma contains charged particles called ions. This gives plasma other interesting properties. For example, it glows with light. Where can you find plasmas? Two examples are shown in Figure 4.7. The sun and other stars consist of plasma. Plasmas are also found naturally in lightning and the polar auroras (northern and southern lights). Artificial plasmas are found in fluorescent lights, plasma TV screens, and plasma balls like the one that opened this chapter. You can learn more about plasmas at this URL: (2:58). MEDIA Click image to the left or use the URL below. URL: Why do different states of matter have different properties? Its because of differences in energy at the level of atoms and molecules, the tiny particles that make up matter. Energy is defined as the ability to cause changes in matter. You can change energy from one form to another when you lift your arm or take a step. In each case, energy is used to move matter you. The energy of moving matter is called kinetic energy. The particles that make up matter are also constantly moving. They have kinetic energy. The theory that all matter consists of constantly moving particles is called the kinetic theory of matter. You can learn more about it at the URL below. Particles of matter of the same substance, such as the same element, are attracted to one another. The force of attraction tends to pull the particles closer together. The particles need a lot of kinetic energy to overcome the force of attraction and move apart. Its like a tug of war between opposing forces. The kinetic energy of individual particles is on one side, and the force of attraction between different particles is on the other side. The outcome of the "war" depends on the state of matter. This is illustrated in Figure 4.8 and in the animation at this URL: http://w In solids, particles dont have enough kinetic energy to overcome the force of attraction between them. The particles are packed closely together and cannot move around. All they can do
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Ice is an example of solid matter. A solid is matter that has a fixed volume and a fixed shape. Figure 4.3 shows examples of matter that are usually solids under Earth conditions. In the figure, salt and cellulose are examples of crystalline solids. The particles of crystalline solids are arranged in a regular repeating pattern. The steaks and candle wax are examples of amorphous ("shapeless") solids. Their particles have no definite pattern. Ocean water is an example of a liquid. A liquid is matter that has a fixed volume but not a fixed shape. Instead, a liquid takes the shape of its container. If the volume of a liquid is less than the volume of its container, the top surface will be exposed to the air, like the oil in the bottles in Figure 4.4. Two interesting properties of liquids are surface tension and viscosity. Surface tension is a force that pulls particles at the exposed surface of a liquid toward other liquid particles. Surface tension explains why water forms droplets, like those in Figure 4.5. Viscosity is a liquids resistance to flowing. Thicker liquids are more viscous than thinner liquids. For example, the honey in Figure 4.5 is more viscous than the vinegar. You can learn more about surface tension and viscosity at these URLs: http://io9.com/5668221/an-experiment-with-soap-water-pepper-and-surface-tension http://chemed.chem.wisc.edu/chempaths/GenChem-Textbook/Viscosity-840.html (1:40) MEDIA Click image to the left or use the URL below. URL: Water vapor is an example of a gas. A gas is matter that has neither a fixed volume nor a fixed shape. Instead, a gas takes both the volume and the shape of its container. It spreads out to take up all available space. You can see an example in Figure 4.6. Youre probably less familiar with plasmas than with solids, liquids, and gases. Yet, most of the universe consists of plasma. Plasma is a state of matter that resembles a gas but has certain properties that a gas does not have. Like a gas, plasma lacks a fixed volume and shape. Unlike a gas, plasma can conduct electricity and respond to magnetism. Thats because plasma contains charged particles called ions. This gives plasma other interesting properties. For example, it glows with light. Where can you find plasmas? Two examples are shown in Figure 4.7. The sun and other stars consist of plasma. Plasmas are also found naturally in lightning and the polar auroras (northern and southern lights). Artificial plasmas are found in fluorescent lights, plasma TV screens, and plasma balls like the one that opened this chapter. You can learn more about plasmas at this URL: (2:58). MEDIA Click image to the left or use the URL below. URL: Why do different states of matter have different properties? Its because of differences in energy at the level of atoms and molecules, the tiny particles that make up matter. Energy is defined as the ability to cause changes in matter. You can change energy from one form to another when you lift your arm or take a step. In each case, energy is used to move matter you. The energy of moving matter is called kinetic energy. The particles that make up matter are also constantly moving. They have kinetic energy. The theory that all matter consists of constantly moving particles is called the kinetic theory of matter. You can learn more about it at the URL below. Particles of matter of the same substance, such as the same element, are attracted to one another. The force of attraction tends to pull the particles closer together. The particles need a lot of kinetic energy to overcome the force of attraction and move apart. Its like a tug of war between opposing forces. The kinetic energy of individual particles is on one side, and the force of attraction between different particles is on the other side. The outcome of the "war" depends on the state of matter. This is illustrated in Figure 4.8 and in the animation at this URL: http://w In solids, particles dont have enough kinetic energy to overcome the force of attraction between them. The particles are packed closely together and cannot move around. All they can do
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Ice is an example of solid matter. A solid is matter that has a fixed volume and a fixed shape. Figure 4.3 shows examples of matter that are usually solids under Earth conditions. In the figure, salt and cellulose are examples of crystalline solids. The particles of crystalline solids are arranged in a regular repeating pattern. The steaks and candle wax are examples of amorphous ("shapeless") solids. Their particles have no definite pattern. Ocean water is an example of a liquid. A liquid is matter that has a fixed volume but not a fixed shape. Instead, a liquid takes the shape of its container. If the volume of a liquid is less than the volume of its container, the top surface will be exposed to the air, like the oil in the bottles in Figure 4.4. Two interesting properties of liquids are surface tension and viscosity. Surface tension is a force that pulls particles at the exposed surface of a liquid toward other liquid particles. Surface tension explains why water forms droplets, like those in Figure 4.5. Viscosity is a liquids resistance to flowing. Thicker liquids are more viscous than thinner liquids. For example, the honey in Figure 4.5 is more viscous than the vinegar. You can learn more about surface tension and viscosity at these URLs: http://io9.com/5668221/an-experiment-with-soap-water-pepper-and-surface-tension http://chemed.chem.wisc.edu/chempaths/GenChem-Textbook/Viscosity-840.html (1:40) MEDIA Click image to the left or use the URL below. URL: Water vapor is an example of a gas. A gas is matter that has neither a fixed volume nor a fixed shape. Instead, a gas takes both the volume and the shape of its container. It spreads out to take up all available space. You can see an example in Figure 4.6. Youre probably less familiar with plasmas than with solids, liquids, and gases. Yet, most of the universe consists of plasma. Plasma is a state of matter that resembles a gas but has certain properties that a gas does not have. Like a gas, plasma lacks a fixed volume and shape. Unlike a gas, plasma can conduct electricity and respond to magnetism. Thats because plasma contains charged particles called ions. This gives plasma other interesting properties. For example, it glows with light. Where can you find plasmas? Two examples are shown in Figure 4.7. The sun and other stars consist of plasma. Plasmas are also found naturally in lightning and the polar auroras (northern and southern lights). Artificial plasmas are found in fluorescent lights, plasma TV screens, and plasma balls like the one that opened this chapter. You can learn more about plasmas at this URL: (2:58). MEDIA Click image to the left or use the URL below. URL: Why do different states of matter have different properties? Its because of differences in energy at the level of atoms and molecules, the tiny particles that make up matter. Energy is defined as the ability to cause changes in matter. You can change energy from one form to another when you lift your arm or take a step. In each case, energy is used to move matter you. The energy of moving matter is called kinetic energy. The particles that make up matter are also constantly moving. They have kinetic energy. The theory that all matter consists of constantly moving particles is called the kinetic theory of matter. You can learn more about it at the URL below. Particles of matter of the same substance, such as the same element, are attracted to one another. The force of attraction tends to pull the particles closer together. The particles need a lot of kinetic energy to overcome the force of attraction and move apart. Its like a tug of war between opposing forces. The kinetic energy of individual particles is on one side, and the force of attraction between different particles is on the other side. The outcome of the "war" depends on the state of matter. This is illustrated in Figure 4.8 and in the animation at this URL: http://w In solids, particles dont have enough kinetic energy to overcome the force of attraction between them. The particles are packed closely together and cannot move around. All they can do
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Ice is an example of solid matter. A solid is matter that has a fixed volume and a fixed shape. Figure 4.3 shows examples of matter that are usually solids under Earth conditions. In the figure, salt and cellulose are examples of crystalline solids. The particles of crystalline solids are arranged in a regular repeating pattern. The steaks and candle wax are examples of amorphous ("shapeless") solids. Their particles have no definite pattern. Ocean water is an example of a liquid. A liquid is matter that has a fixed volume but not a fixed shape. Instead, a liquid takes the shape of its container. If the volume of a liquid is less than the volume of its container, the top surface will be exposed to the air, like the oil in the bottles in Figure 4.4. Two interesting properties of liquids are surface tension and viscosity. Surface tension is a force that pulls particles at the exposed surface of a liquid toward other liquid particles. Surface tension explains why water forms droplets, like those in Figure 4.5. Viscosity is a liquids resistance to flowing. Thicker liquids are more viscous than thinner liquids. For example, the honey in Figure 4.5 is more viscous than the vinegar. You can learn more about surface tension and viscosity at these URLs: http://io9.com/5668221/an-experiment-with-soap-water-pepper-and-surface-tension http://chemed.chem.wisc.edu/chempaths/GenChem-Textbook/Viscosity-840.html (1:40) MEDIA Click image to the left or use the URL below. URL: Water vapor is an example of a gas. A gas is matter that has neither a fixed volume nor a fixed shape. Instead, a gas takes both the volume and the shape of its container. It spreads out to take up all available space. You can see an example in Figure 4.6. Youre probably less familiar with plasmas than with solids, liquids, and gases. Yet, most of the universe consists of plasma. Plasma is a state of matter that resembles a gas but has certain properties that a gas does not have. Like a gas, plasma lacks a fixed volume and shape. Unlike a gas, plasma can conduct electricity and respond to magnetism. Thats because plasma contains charged particles called ions. This gives plasma other interesting properties. For example, it glows with light. Where can you find plasmas? Two examples are shown in Figure 4.7. The sun and other stars consist of plasma. Plasmas are also found naturally in lightning and the polar auroras (northern and southern lights). Artificial plasmas are found in fluorescent lights, plasma TV screens, and plasma balls like the one that opened this chapter. You can learn more about plasmas at this URL: (2:58). MEDIA Click image to the left or use the URL below. URL: Why do different states of matter have different properties? Its because of differences in energy at the level of atoms and molecules, the tiny particles that make up matter. Energy is defined as the ability to cause changes in matter. You can change energy from one form to another when you lift your arm or take a step. In each case, energy is used to move matter you. The energy of moving matter is called kinetic energy. The particles that make up matter are also constantly moving. They have kinetic energy. The theory that all matter consists of constantly moving particles is called the kinetic theory of matter. You can learn more about it at the URL below. Particles of matter of the same substance, such as the same element, are attracted to one another. The force of attraction tends to pull the particles closer together. The particles need a lot of kinetic energy to overcome the force of attraction and move apart. Its like a tug of war between opposing forces. The kinetic energy of individual particles is on one side, and the force of attraction between different particles is on the other side. The outcome of the "war" depends on the state of matter. This is illustrated in Figure 4.8 and in the animation at this URL: http://w In solids, particles dont have enough kinetic energy to overcome the force of attraction between them. The particles are packed closely together and cannot move around. All they can do
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Ice is an example of solid matter. A solid is matter that has a fixed volume and a fixed shape. Figure 4.3 shows examples of matter that are usually solids under Earth conditions. In the figure, salt and cellulose are examples of crystalline solids. The particles of crystalline solids are arranged in a regular repeating pattern. The steaks and candle wax are examples of amorphous ("shapeless") solids. Their particles have no definite pattern. Ocean water is an example of a liquid. A liquid is matter that has a fixed volume but not a fixed shape. Instead, a liquid takes the shape of its container. If the volume of a liquid is less than the volume of its container, the top surface will be exposed to the air, like the oil in the bottles in Figure 4.4. Two interesting properties of liquids are surface tension and viscosity. Surface tension is a force that pulls particles at the exposed surface of a liquid toward other liquid particles. Surface tension explains why water forms droplets, like those in Figure 4.5. Viscosity is a liquids resistance to flowing. Thicker liquids are more viscous than thinner liquids. For example, the honey in Figure 4.5 is more viscous than the vinegar. You can learn more about surface tension and viscosity at these URLs: http://io9.com/5668221/an-experiment-with-soap-water-pepper-and-surface-tension http://chemed.chem.wisc.edu/chempaths/GenChem-Textbook/Viscosity-840.html (1:40) MEDIA Click image to the left or use the URL below. URL: Water vapor is an example of a gas. A gas is matter that has neither a fixed volume nor a fixed shape. Instead, a gas takes both the volume and the shape of its container. It spreads out to take up all available space. You can see an example in Figure 4.6. Youre probably less familiar with plasmas than with solids, liquids, and gases. Yet, most of the universe consists of plasma. Plasma is a state of matter that resembles a gas but has certain properties that a gas does not have. Like a gas, plasma lacks a fixed volume and shape. Unlike a gas, plasma can conduct electricity and respond to magnetism. Thats because plasma contains charged particles called ions. This gives plasma other interesting properties. For example, it glows with light. Where can you find plasmas? Two examples are shown in Figure 4.7. The sun and other stars consist of plasma. Plasmas are also found naturally in lightning and the polar auroras (northern and southern lights). Artificial plasmas are found in fluorescent lights, plasma TV screens, and plasma balls like the one that opened this chapter. You can learn more about plasmas at this URL: (2:58). MEDIA Click image to the left or use the URL below. URL: Why do different states of matter have different properties? Its because of differences in energy at the level of atoms and molecules, the tiny particles that make up matter. Energy is defined as the ability to cause changes in matter. You can change energy from one form to another when you lift your arm or take a step. In each case, energy is used to move matter you. The energy of moving matter is called kinetic energy. The particles that make up matter are also constantly moving. They have kinetic energy. The theory that all matter consists of constantly moving particles is called the kinetic theory of matter. You can learn more about it at the URL below. Particles of matter of the same substance, such as the same element, are attracted to one another. The force of attraction tends to pull the particles closer together. The particles need a lot of kinetic energy to overcome the force of attraction and move apart. Its like a tug of war between opposing forces. The kinetic energy of individual particles is on one side, and the force of attraction between different particles is on the other side. The outcome of the "war" depends on the state of matter. This is illustrated in Figure 4.8 and in the animation at this URL: http://w In solids, particles dont have enough kinetic energy to overcome the force of attraction between them. The particles are packed closely together and cannot move around. All they can do
|
Surface tension is a force that affects
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Ice is an example of solid matter. A solid is matter that has a fixed volume and a fixed shape. Figure 4.3 shows examples of matter that are usually solids under Earth conditions. In the figure, salt and cellulose are examples of crystalline solids. The particles of crystalline solids are arranged in a regular repeating pattern. The steaks and candle wax are examples of amorphous ("shapeless") solids. Their particles have no definite pattern. Ocean water is an example of a liquid. A liquid is matter that has a fixed volume but not a fixed shape. Instead, a liquid takes the shape of its container. If the volume of a liquid is less than the volume of its container, the top surface will be exposed to the air, like the oil in the bottles in Figure 4.4. Two interesting properties of liquids are surface tension and viscosity. Surface tension is a force that pulls particles at the exposed surface of a liquid toward other liquid particles. Surface tension explains why water forms droplets, like those in Figure 4.5. Viscosity is a liquids resistance to flowing. Thicker liquids are more viscous than thinner liquids. For example, the honey in Figure 4.5 is more viscous than the vinegar. You can learn more about surface tension and viscosity at these URLs: http://io9.com/5668221/an-experiment-with-soap-water-pepper-and-surface-tension http://chemed.chem.wisc.edu/chempaths/GenChem-Textbook/Viscosity-840.html (1:40) MEDIA Click image to the left or use the URL below. URL: Water vapor is an example of a gas. A gas is matter that has neither a fixed volume nor a fixed shape. Instead, a gas takes both the volume and the shape of its container. It spreads out to take up all available space. You can see an example in Figure 4.6. Youre probably less familiar with plasmas than with solids, liquids, and gases. Yet, most of the universe consists of plasma. Plasma is a state of matter that resembles a gas but has certain properties that a gas does not have. Like a gas, plasma lacks a fixed volume and shape. Unlike a gas, plasma can conduct electricity and respond to magnetism. Thats because plasma contains charged particles called ions. This gives plasma other interesting properties. For example, it glows with light. Where can you find plasmas? Two examples are shown in Figure 4.7. The sun and other stars consist of plasma. Plasmas are also found naturally in lightning and the polar auroras (northern and southern lights). Artificial plasmas are found in fluorescent lights, plasma TV screens, and plasma balls like the one that opened this chapter. You can learn more about plasmas at this URL: (2:58). MEDIA Click image to the left or use the URL below. URL: Why do different states of matter have different properties? Its because of differences in energy at the level of atoms and molecules, the tiny particles that make up matter. Energy is defined as the ability to cause changes in matter. You can change energy from one form to another when you lift your arm or take a step. In each case, energy is used to move matter you. The energy of moving matter is called kinetic energy. The particles that make up matter are also constantly moving. They have kinetic energy. The theory that all matter consists of constantly moving particles is called the kinetic theory of matter. You can learn more about it at the URL below. Particles of matter of the same substance, such as the same element, are attracted to one another. The force of attraction tends to pull the particles closer together. The particles need a lot of kinetic energy to overcome the force of attraction and move apart. Its like a tug of war between opposing forces. The kinetic energy of individual particles is on one side, and the force of attraction between different particles is on the other side. The outcome of the "war" depends on the state of matter. This is illustrated in Figure 4.8 and in the animation at this URL: http://w In solids, particles dont have enough kinetic energy to overcome the force of attraction between them. The particles are packed closely together and cannot move around. All they can do
|
Which state of matter has particles with the least energy?
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The male reproductive organs include the penis, testes, and epididymis ( Figure 1.1). The figure also shows other parts of the male reproductive system. The penis is a cylinder-shaped organ. It contains the urethra. The urethra is a tube that carries urine out of the body. The urethra also carries sperm out of the body. This drawing shows the organs of the male reproductive system. It shows the organs from the side. Find each organ in the drawing as you read about it in the text. The two testes (singular, testis) are egg-shaped organs. They produce sperm and secrete testosterone. The testes are found inside of the scrotum. The scrotum is a sac that hangs down outside the body. The scrotum also contains the epididymis. The testes, being in the scrotum outside the body, allow the temperature of the sperm to be maintained at a few degrees lower than body temperature. This is necessary for the stability of these reproductive cells. The epididymis is a tube that is about six meters (20 feet) long in adults. It is tightly coiled, so it fits inside the scrotum. It rests on top of the testes. The epididymis is where sperm grow larger and mature. The epididymis also stores sperm until they leave the body. Other parts of the male reproductive system include the vas deferens and the prostate gland. Both of these structures are pictured below ( Figure 1.1). The vas deferens is a tube that carries sperm from the epididymis to the urethra. The prostate gland secretes a fluid that mixes with sperm to help form semen. The prostate gland is located beneath the bladder. Semen is a "milky" liquid that carries sperm through the urethra and out of the body. In addition to sperm cells, semen contains sugars (fructose) which provide energy to the sperm cells, and enzymes and other substances which help the sperm survive.
|
what is the organ where sperm cells mature?
|
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"epididymis"
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The male reproductive organs include the penis, testes, and epididymis ( Figure 1.1). The figure also shows other parts of the male reproductive system. The penis is a cylinder-shaped organ. It contains the urethra. The urethra is a tube that carries urine out of the body. The urethra also carries sperm out of the body. This drawing shows the organs of the male reproductive system. It shows the organs from the side. Find each organ in the drawing as you read about it in the text. The two testes (singular, testis) are egg-shaped organs. They produce sperm and secrete testosterone. The testes are found inside of the scrotum. The scrotum is a sac that hangs down outside the body. The scrotum also contains the epididymis. The testes, being in the scrotum outside the body, allow the temperature of the sperm to be maintained at a few degrees lower than body temperature. This is necessary for the stability of these reproductive cells. The epididymis is a tube that is about six meters (20 feet) long in adults. It is tightly coiled, so it fits inside the scrotum. It rests on top of the testes. The epididymis is where sperm grow larger and mature. The epididymis also stores sperm until they leave the body. Other parts of the male reproductive system include the vas deferens and the prostate gland. Both of these structures are pictured below ( Figure 1.1). The vas deferens is a tube that carries sperm from the epididymis to the urethra. The prostate gland secretes a fluid that mixes with sperm to help form semen. The prostate gland is located beneath the bladder. Semen is a "milky" liquid that carries sperm through the urethra and out of the body. In addition to sperm cells, semen contains sugars (fructose) which provide energy to the sperm cells, and enzymes and other substances which help the sperm survive.
|
what organ allows sperm cells to travel to the urethra?
|
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The male reproductive organs include the penis, testes, and epididymis ( Figure 1.1). The figure also shows other parts of the male reproductive system. The penis is a cylinder-shaped organ. It contains the urethra. The urethra is a tube that carries urine out of the body. The urethra also carries sperm out of the body. This drawing shows the organs of the male reproductive system. It shows the organs from the side. Find each organ in the drawing as you read about it in the text. The two testes (singular, testis) are egg-shaped organs. They produce sperm and secrete testosterone. The testes are found inside of the scrotum. The scrotum is a sac that hangs down outside the body. The scrotum also contains the epididymis. The testes, being in the scrotum outside the body, allow the temperature of the sperm to be maintained at a few degrees lower than body temperature. This is necessary for the stability of these reproductive cells. The epididymis is a tube that is about six meters (20 feet) long in adults. It is tightly coiled, so it fits inside the scrotum. It rests on top of the testes. The epididymis is where sperm grow larger and mature. The epididymis also stores sperm until they leave the body. Other parts of the male reproductive system include the vas deferens and the prostate gland. Both of these structures are pictured below ( Figure 1.1). The vas deferens is a tube that carries sperm from the epididymis to the urethra. The prostate gland secretes a fluid that mixes with sperm to help form semen. The prostate gland is located beneath the bladder. Semen is a "milky" liquid that carries sperm through the urethra and out of the body. In addition to sperm cells, semen contains sugars (fructose) which provide energy to the sperm cells, and enzymes and other substances which help the sperm survive.
|
semen is formed with a fluid secreted by the
|
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"prostate gland."
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The male reproductive organs include the penis, testes, and epididymis ( Figure 1.1). The figure also shows other parts of the male reproductive system. The penis is a cylinder-shaped organ. It contains the urethra. The urethra is a tube that carries urine out of the body. The urethra also carries sperm out of the body. This drawing shows the organs of the male reproductive system. It shows the organs from the side. Find each organ in the drawing as you read about it in the text. The two testes (singular, testis) are egg-shaped organs. They produce sperm and secrete testosterone. The testes are found inside of the scrotum. The scrotum is a sac that hangs down outside the body. The scrotum also contains the epididymis. The testes, being in the scrotum outside the body, allow the temperature of the sperm to be maintained at a few degrees lower than body temperature. This is necessary for the stability of these reproductive cells. The epididymis is a tube that is about six meters (20 feet) long in adults. It is tightly coiled, so it fits inside the scrotum. It rests on top of the testes. The epididymis is where sperm grow larger and mature. The epididymis also stores sperm until they leave the body. Other parts of the male reproductive system include the vas deferens and the prostate gland. Both of these structures are pictured below ( Figure 1.1). The vas deferens is a tube that carries sperm from the epididymis to the urethra. The prostate gland secretes a fluid that mixes with sperm to help form semen. The prostate gland is located beneath the bladder. Semen is a "milky" liquid that carries sperm through the urethra and out of the body. In addition to sperm cells, semen contains sugars (fructose) which provide energy to the sperm cells, and enzymes and other substances which help the sperm survive.
|
what organ or gland sits on top of the testes?
|
[
"the epididymis"
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The male reproductive organs include the penis, testes, and epididymis ( Figure 1.1). The figure also shows other parts of the male reproductive system. The penis is a cylinder-shaped organ. It contains the urethra. The urethra is a tube that carries urine out of the body. The urethra also carries sperm out of the body. This drawing shows the organs of the male reproductive system. It shows the organs from the side. Find each organ in the drawing as you read about it in the text. The two testes (singular, testis) are egg-shaped organs. They produce sperm and secrete testosterone. The testes are found inside of the scrotum. The scrotum is a sac that hangs down outside the body. The scrotum also contains the epididymis. The testes, being in the scrotum outside the body, allow the temperature of the sperm to be maintained at a few degrees lower than body temperature. This is necessary for the stability of these reproductive cells. The epididymis is a tube that is about six meters (20 feet) long in adults. It is tightly coiled, so it fits inside the scrotum. It rests on top of the testes. The epididymis is where sperm grow larger and mature. The epididymis also stores sperm until they leave the body. Other parts of the male reproductive system include the vas deferens and the prostate gland. Both of these structures are pictured below ( Figure 1.1). The vas deferens is a tube that carries sperm from the epididymis to the urethra. The prostate gland secretes a fluid that mixes with sperm to help form semen. The prostate gland is located beneath the bladder. Semen is a "milky" liquid that carries sperm through the urethra and out of the body. In addition to sperm cells, semen contains sugars (fructose) which provide energy to the sperm cells, and enzymes and other substances which help the sperm survive.
|
what organ or gland surrounds the urethra just below the bladder?
|
[
"the prostate gland"
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How do you test a hypothesis? In this example, we will look into the scientific literature to find data in studies that were done using scientific method. To test Hypothesis 1 from the concept "Development of Hypotheses," we need to see if the amount of CO2 gas released by volcanoes over the past several decades has increased. There are two ways volcanoes could account for the increase in CO2 : There has been an increase in volcanic eruptions in that time. The CO2 content of volcanic gases has increased over time globally. To test the first hypothesis, we look at the scientific literature. We see that the number of volcanic eruptions is about constant. We also learn from the scientific literature that volcanic gas compositions have not changed over time. Different types of volcanoes have different gas compositions, but overall the gases are the same. Another journal article states that major volcanic eruptions for the past 30 years have caused short-term cooling, not warming! Hypothesis 1 is wrong! Volcanic activity is not able to account for the rise in atmospheric CO2 . Remember that science is falsifiable. We can discard Hypothesis 1. Hypothesis 2 states that the increase in atmospheric CO2 is due to the increase in the amount of fossil fuels that are being burned. We look into the scientific literature and find this graph in the Figure 1.1. Global carbon dioxide emissions from fos- sil fuel consumption and cement produc- tion. The black line represents all emis- sion types combined, and colored lines show emissions from individual fossil fu- els. Fossil fuels have added an increasing amount of carbon dioxide to the atmosphere since the beginning of the Industrial Revolution in the mid 19th century. Hypothesis 2 is true! Click image to the left or use the URL below. URL:
|
a series of steps that help to investigate a scientific question is
|
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"the scientific method"
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Bases are ionic compounds that produce negative hydroxide ions (OH ) when dissolved in water. An ionic com- pound contains positive metal ions and negative nonmetal ions held together by ionic bonds. (Ions are atoms that have become charged particles because they have either lost or gained electrons.) An example of a base is sodium hydroxide (NaOH). When it dissolves in water, it produces negative hydroxide ions and positive sodium ions (Na+ ). This can be represented by the equation: H O 2 NaOH OH + Na+ All bases share certain properties, including a bitter taste. (Warning: Never taste an unknown substance to see whether it is a base!) Bases also feel slippery. Think about how slippery soap feels. Thats because its a base. In addition, bases conduct electricity when dissolved in water because they consist of charged particles in solution. (Electric current is a flow of charged particles.) Q: Bases are closely related to compounds called acids. How are their properties similar? How are they different? A: A property that is shared by bases and acids is the ability to conduct electricity when dissolved in water. Some ways bases and acids are different is that acids taste sour whereas bases taste bitter. Also, acids but not bases react with metals. Certain compounds, called indicators, change color when bases come into contact with them, so they can be used to detect bases. An example of an indicator is a compound called litmus. It is placed on small strips of paper that may be red or blue. If you place a few drops of a base on a strip of red litmus paper, the paper will turn blue. You can see this in the Figure 1.1. Litmus isnt the only detector of bases. Red cabbage juice can also detect bases, as you can see in this video. Click image to the left or use the URL below. URL: Drawing of red litmus paper turning blue in a base. The strength of bases is measured on a scale called the pH scale, which ranges from 0 to 14. On this scale, a pH value of 7 indicates a neutral solution, and a pH value greater than 7 indicates a basic solution. The higher the pH value is, the stronger the base. The strongest bases, such as drain cleaner, have a pH value close to 14. Bases are used for a variety of purposes. For example, soaps contain bases such as potassium hydroxide (KOH). Other uses of bases can be seen in the Figure 1.2.
|
the strongest bases have ph values close to
|
[
"14"
] |
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A chemical reaction is a process in which some substances change into different substances. Substances that start a chemical reaction are called reactants. Substances that are produced in the reaction are called products. Reactants and products can be elements or compounds. Chemical reactions are represented by chemical equations, like the one below, in which reactants (on the left) are connected by an arrow to products (on the right). Reactants Products Chemical reactions may occur quickly or slowly. Look at the two pictures in the Figure 1.1. Both represent chemical reactions. In the picture on the left, a reaction inside a fire extinguisher causes foam to shoot out of the extinguisher. This reaction occurs almost instantly. In the picture on the right, a reaction causes the iron tool to turn to rust. This reaction occurs very slowly. In fact, it might take many years for all of the iron in the tool to turn to rust. Q: What happens during a chemical reaction? Where do the reactants go, and where do the products come from? A: During a chemical reaction, chemical changes take place. Some chemical bonds break and new chemical bonds form. The reactants and products in a chemical reaction contain the same atoms, but they are rearranged during the reaction. As a result, the atoms are in different combinations in the products than they were in the reactants. This happens because chemical bonds break in the reactants and new chemical bonds form in the products. Consider the chemical reaction in which water forms from oxygen and hydrogen gases. The Figure 1.2 represents this reaction. Bonds break in molecules of hydrogen and oxygen, and then new bonds form in molecules of water. In both reactants and products there are four hydrogen atoms and two oxygen atoms, but the atoms are combined differently in water. The chemical reaction in the Figure 1.2, in which water forms from hydrogen and oxygen, is an example of a synthesis reaction. In this type of reaction, two or more reactants combine to synthesize a single product. There are several other types of chemical reactions, including decomposition, replacement, and combustion reactions. The Table 1.1 compares these four types of chemical reactions. Type of Reaction Synthesis Decomposition General Equation A+B C AB A + B Example 2Na + Cl2 2NaCl 2H2 O 2H2 + O2 Type of Reaction Single Replacement Double Replacement Combustion General Equation A+BC B+ AC AB+ CD AD + CB fuel + oxygen carbon dioxide + water Example 2K + 2H2 O 2KOH + H2 NaCl+ AgF NaF + AgCl CH4 + 2O2 CO2 + 2H2 O Q: The burning of wood is a chemical reaction. Which type of reaction is it? A: The burning of woodor of anything elseis a combustion reaction. In the combustion example in the table, the fuel is methane gas (CH4 ). Click image to the left or use the URL below. URL: All chemical reactions involve energy. Energy is used to break bonds in reactants, and energy is released when new bonds form in products. In terms of energy, there are two types of chemical reactions: endothermic reactions and exothermic reactions. In exothermic reactions, more energy is released when bonds form in products than is used to break bonds in reactants. These reactions release energy to the environment, often in the form of heat or light. In endothermic reactions, more energy is used to break bonds in reactants than is released when bonds form in products. These reactions absorb energy from the environment. Q: When it comes to energy, which type of reaction is the burning of wood? Is it an endothermic reaction or an exothermic reaction? How can you tell? A: The burning of wood is an exothermic reaction. You can tell by the heat and light energy given off by a wood fire.
|
during a chemical reaction
|
[
"chemical bonds break."
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Flatworms are invertebrates that belong to Phylum Platyhelminthes. There are more than 25,000 species in the flatworm phylum. Not all flatworms are as long as tapeworms. Some are only about a millimeter in length. Flatworms have a flat body because they lack a fluid-filled body cavity. They also have an incomplete digestive system with a single opening. However, flatworms represent several evolutionary advances in invertebrates. They have the following adaptations: Flatworms have three embryonic cell layers. They have a mesoderm layer in addition to ectoderm and endoderm layers. The mesoderm layer allows flatworms to develop muscle tissues so they can move easily over solid surfaces. Flatworms have a concentration of nerve tissue in the head end. This was a major step in the evolution of a brain. It was also needed for bilateral symmetry. Flatworms have bilateral symmetry. This gives them a better sense of direction than radial symmetry would. Watch this amazing flatworm video to learn about some of the other firsts these simple animals achieved, including being the first hunters: http://shapeoflife.org/video/flatworms-first-hunter MEDIA Click image to the left or use the URL below. URL: Flatworms reproduce sexually. In most species, the same individuals produce both eggs and sperm. After fertilization occurs, the fertilized eggs pass out of the adults body and hatch into larvae. There may be several different larval stages. The final larval stage develops into the adult form. Then the life cycle repeats. Some flatworms live in water or moist soil. They eat invertebrates and decaying animals. Other flatworms, such as tapeworms, are parasites that live inside vertebrate hosts. Usually, more than one type of host is needed to complete the parasites life cycle, as shown in Figure 12.12. Roundworms are invertebrates in Phylum Nematoda. This is a very diverse phylum. It has more than 80,000 known species. Roundworms range in length from less than 1 millimeter to over 7 meters in length. You can see an example of a roundworm in Figure 12.13. Roundworms have a round body because they have a partial fluid-filled body cavity (pseudocoelom). This is one way that roundworms differ from flatworms. Another way is their complete digestive system. It allows them to eat, digest food, and eliminate wastes all at the same time. Roundworms have a tough covering of cuticle on the surface of their body. It prevents their body from expanding. This allows the buildup of fluid pressure in their partial body cavity. The fluid pressure adds stiffness to the body. This provides a counterforce for the contraction of muscles, allowing roundworms to move easily over surfaces. Roundworms reproduce sexually. Sperm and eggs are produced by separate male and female adults. Fertilization takes place inside the female organism. Females lay huge numbers of eggs, sometimes as many as 100,000 per day! The eggs hatch into larvae, which develop into adults. Then the life cycle repeats. Roundworms may be free-living or parasitic organisms. Free-living worms are found mainly in freshwater habitats. Some live in moist soil. They generally feed on bacteria, fungi, protozoa, or decaying organic matter. By breaking down organic matter, they play an important role in the carbon cycle. Parasitic roundworms may have plant, invertebrate, or vertebrate hosts. Several roundworm species infect humans. Besides ascaris, they include hookworms. Hookworms are named for the hooks they use to grab onto the hosts intestines. You can see the hooks in Figure 12.14. Hookworm larvae enter the host through the skin. They migrate to the intestine, where they mature into adults. Female adults lay large quantities of eggs. Eggs pass out of the host in feces. Eggs hatch into larvae in the feces or soil. Then the cycle repeats. You can learn more about parasitic roundworms in humans by watching this short video: . MEDIA Click image to the left or use the URL below. URL:
|
How many species belong to Phylum Platyhelminthes?
|
[
"more than 25,000"
] |
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Flatworms are invertebrates that belong to Phylum Platyhelminthes. There are more than 25,000 species in the flatworm phylum. Not all flatworms are as long as tapeworms. Some are only about a millimeter in length. Flatworms have a flat body because they lack a fluid-filled body cavity. They also have an incomplete digestive system with a single opening. However, flatworms represent several evolutionary advances in invertebrates. They have the following adaptations: Flatworms have three embryonic cell layers. They have a mesoderm layer in addition to ectoderm and endoderm layers. The mesoderm layer allows flatworms to develop muscle tissues so they can move easily over solid surfaces. Flatworms have a concentration of nerve tissue in the head end. This was a major step in the evolution of a brain. It was also needed for bilateral symmetry. Flatworms have bilateral symmetry. This gives them a better sense of direction than radial symmetry would. Watch this amazing flatworm video to learn about some of the other firsts these simple animals achieved, including being the first hunters: http://shapeoflife.org/video/flatworms-first-hunter MEDIA Click image to the left or use the URL below. URL: Flatworms reproduce sexually. In most species, the same individuals produce both eggs and sperm. After fertilization occurs, the fertilized eggs pass out of the adults body and hatch into larvae. There may be several different larval stages. The final larval stage develops into the adult form. Then the life cycle repeats. Some flatworms live in water or moist soil. They eat invertebrates and decaying animals. Other flatworms, such as tapeworms, are parasites that live inside vertebrate hosts. Usually, more than one type of host is needed to complete the parasites life cycle, as shown in Figure 12.12. Roundworms are invertebrates in Phylum Nematoda. This is a very diverse phylum. It has more than 80,000 known species. Roundworms range in length from less than 1 millimeter to over 7 meters in length. You can see an example of a roundworm in Figure 12.13. Roundworms have a round body because they have a partial fluid-filled body cavity (pseudocoelom). This is one way that roundworms differ from flatworms. Another way is their complete digestive system. It allows them to eat, digest food, and eliminate wastes all at the same time. Roundworms have a tough covering of cuticle on the surface of their body. It prevents their body from expanding. This allows the buildup of fluid pressure in their partial body cavity. The fluid pressure adds stiffness to the body. This provides a counterforce for the contraction of muscles, allowing roundworms to move easily over surfaces. Roundworms reproduce sexually. Sperm and eggs are produced by separate male and female adults. Fertilization takes place inside the female organism. Females lay huge numbers of eggs, sometimes as many as 100,000 per day! The eggs hatch into larvae, which develop into adults. Then the life cycle repeats. Roundworms may be free-living or parasitic organisms. Free-living worms are found mainly in freshwater habitats. Some live in moist soil. They generally feed on bacteria, fungi, protozoa, or decaying organic matter. By breaking down organic matter, they play an important role in the carbon cycle. Parasitic roundworms may have plant, invertebrate, or vertebrate hosts. Several roundworm species infect humans. Besides ascaris, they include hookworms. Hookworms are named for the hooks they use to grab onto the hosts intestines. You can see the hooks in Figure 12.14. Hookworm larvae enter the host through the skin. They migrate to the intestine, where they mature into adults. Female adults lay large quantities of eggs. Eggs pass out of the host in feces. Eggs hatch into larvae in the feces or soil. Then the cycle repeats. You can learn more about parasitic roundworms in humans by watching this short video: . MEDIA Click image to the left or use the URL below. URL:
|
All flatworms
|
[
"have a concentration of nerve tissue in the head end"
] |
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Flatworms are invertebrates that belong to Phylum Platyhelminthes. There are more than 25,000 species in the flatworm phylum. Not all flatworms are as long as tapeworms. Some are only about a millimeter in length. Flatworms have a flat body because they lack a fluid-filled body cavity. They also have an incomplete digestive system with a single opening. However, flatworms represent several evolutionary advances in invertebrates. They have the following adaptations: Flatworms have three embryonic cell layers. They have a mesoderm layer in addition to ectoderm and endoderm layers. The mesoderm layer allows flatworms to develop muscle tissues so they can move easily over solid surfaces. Flatworms have a concentration of nerve tissue in the head end. This was a major step in the evolution of a brain. It was also needed for bilateral symmetry. Flatworms have bilateral symmetry. This gives them a better sense of direction than radial symmetry would. Watch this amazing flatworm video to learn about some of the other firsts these simple animals achieved, including being the first hunters: http://shapeoflife.org/video/flatworms-first-hunter MEDIA Click image to the left or use the URL below. URL: Flatworms reproduce sexually. In most species, the same individuals produce both eggs and sperm. After fertilization occurs, the fertilized eggs pass out of the adults body and hatch into larvae. There may be several different larval stages. The final larval stage develops into the adult form. Then the life cycle repeats. Some flatworms live in water or moist soil. They eat invertebrates and decaying animals. Other flatworms, such as tapeworms, are parasites that live inside vertebrate hosts. Usually, more than one type of host is needed to complete the parasites life cycle, as shown in Figure 12.12. Roundworms are invertebrates in Phylum Nematoda. This is a very diverse phylum. It has more than 80,000 known species. Roundworms range in length from less than 1 millimeter to over 7 meters in length. You can see an example of a roundworm in Figure 12.13. Roundworms have a round body because they have a partial fluid-filled body cavity (pseudocoelom). This is one way that roundworms differ from flatworms. Another way is their complete digestive system. It allows them to eat, digest food, and eliminate wastes all at the same time. Roundworms have a tough covering of cuticle on the surface of their body. It prevents their body from expanding. This allows the buildup of fluid pressure in their partial body cavity. The fluid pressure adds stiffness to the body. This provides a counterforce for the contraction of muscles, allowing roundworms to move easily over surfaces. Roundworms reproduce sexually. Sperm and eggs are produced by separate male and female adults. Fertilization takes place inside the female organism. Females lay huge numbers of eggs, sometimes as many as 100,000 per day! The eggs hatch into larvae, which develop into adults. Then the life cycle repeats. Roundworms may be free-living or parasitic organisms. Free-living worms are found mainly in freshwater habitats. Some live in moist soil. They generally feed on bacteria, fungi, protozoa, or decaying organic matter. By breaking down organic matter, they play an important role in the carbon cycle. Parasitic roundworms may have plant, invertebrate, or vertebrate hosts. Several roundworm species infect humans. Besides ascaris, they include hookworms. Hookworms are named for the hooks they use to grab onto the hosts intestines. You can see the hooks in Figure 12.14. Hookworm larvae enter the host through the skin. They migrate to the intestine, where they mature into adults. Female adults lay large quantities of eggs. Eggs pass out of the host in feces. Eggs hatch into larvae in the feces or soil. Then the cycle repeats. You can learn more about parasitic roundworms in humans by watching this short video: . MEDIA Click image to the left or use the URL below. URL:
|
The body of a roundworm is covered with
|
[
"cuticle"
] |
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|
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Flatworms are invertebrates that belong to Phylum Platyhelminthes. There are more than 25,000 species in the flatworm phylum. Not all flatworms are as long as tapeworms. Some are only about a millimeter in length. Flatworms have a flat body because they lack a fluid-filled body cavity. They also have an incomplete digestive system with a single opening. However, flatworms represent several evolutionary advances in invertebrates. They have the following adaptations: Flatworms have three embryonic cell layers. They have a mesoderm layer in addition to ectoderm and endoderm layers. The mesoderm layer allows flatworms to develop muscle tissues so they can move easily over solid surfaces. Flatworms have a concentration of nerve tissue in the head end. This was a major step in the evolution of a brain. It was also needed for bilateral symmetry. Flatworms have bilateral symmetry. This gives them a better sense of direction than radial symmetry would. Watch this amazing flatworm video to learn about some of the other firsts these simple animals achieved, including being the first hunters: http://shapeoflife.org/video/flatworms-first-hunter MEDIA Click image to the left or use the URL below. URL: Flatworms reproduce sexually. In most species, the same individuals produce both eggs and sperm. After fertilization occurs, the fertilized eggs pass out of the adults body and hatch into larvae. There may be several different larval stages. The final larval stage develops into the adult form. Then the life cycle repeats. Some flatworms live in water or moist soil. They eat invertebrates and decaying animals. Other flatworms, such as tapeworms, are parasites that live inside vertebrate hosts. Usually, more than one type of host is needed to complete the parasites life cycle, as shown in Figure 12.12. Roundworms are invertebrates in Phylum Nematoda. This is a very diverse phylum. It has more than 80,000 known species. Roundworms range in length from less than 1 millimeter to over 7 meters in length. You can see an example of a roundworm in Figure 12.13. Roundworms have a round body because they have a partial fluid-filled body cavity (pseudocoelom). This is one way that roundworms differ from flatworms. Another way is their complete digestive system. It allows them to eat, digest food, and eliminate wastes all at the same time. Roundworms have a tough covering of cuticle on the surface of their body. It prevents their body from expanding. This allows the buildup of fluid pressure in their partial body cavity. The fluid pressure adds stiffness to the body. This provides a counterforce for the contraction of muscles, allowing roundworms to move easily over surfaces. Roundworms reproduce sexually. Sperm and eggs are produced by separate male and female adults. Fertilization takes place inside the female organism. Females lay huge numbers of eggs, sometimes as many as 100,000 per day! The eggs hatch into larvae, which develop into adults. Then the life cycle repeats. Roundworms may be free-living or parasitic organisms. Free-living worms are found mainly in freshwater habitats. Some live in moist soil. They generally feed on bacteria, fungi, protozoa, or decaying organic matter. By breaking down organic matter, they play an important role in the carbon cycle. Parasitic roundworms may have plant, invertebrate, or vertebrate hosts. Several roundworm species infect humans. Besides ascaris, they include hookworms. Hookworms are named for the hooks they use to grab onto the hosts intestines. You can see the hooks in Figure 12.14. Hookworm larvae enter the host through the skin. They migrate to the intestine, where they mature into adults. Female adults lay large quantities of eggs. Eggs pass out of the host in feces. Eggs hatch into larvae in the feces or soil. Then the cycle repeats. You can learn more about parasitic roundworms in humans by watching this short video: . MEDIA Click image to the left or use the URL below. URL:
|
Which statement about roundworm reproduction is true?
|
[
"Eggs hatch into larvae, which develop into adults"
] |
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Flatworms are invertebrates that belong to Phylum Platyhelminthes. There are more than 25,000 species in the flatworm phylum. Not all flatworms are as long as tapeworms. Some are only about a millimeter in length. Flatworms have a flat body because they lack a fluid-filled body cavity. They also have an incomplete digestive system with a single opening. However, flatworms represent several evolutionary advances in invertebrates. They have the following adaptations: Flatworms have three embryonic cell layers. They have a mesoderm layer in addition to ectoderm and endoderm layers. The mesoderm layer allows flatworms to develop muscle tissues so they can move easily over solid surfaces. Flatworms have a concentration of nerve tissue in the head end. This was a major step in the evolution of a brain. It was also needed for bilateral symmetry. Flatworms have bilateral symmetry. This gives them a better sense of direction than radial symmetry would. Watch this amazing flatworm video to learn about some of the other firsts these simple animals achieved, including being the first hunters: http://shapeoflife.org/video/flatworms-first-hunter MEDIA Click image to the left or use the URL below. URL: Flatworms reproduce sexually. In most species, the same individuals produce both eggs and sperm. After fertilization occurs, the fertilized eggs pass out of the adults body and hatch into larvae. There may be several different larval stages. The final larval stage develops into the adult form. Then the life cycle repeats. Some flatworms live in water or moist soil. They eat invertebrates and decaying animals. Other flatworms, such as tapeworms, are parasites that live inside vertebrate hosts. Usually, more than one type of host is needed to complete the parasites life cycle, as shown in Figure 12.12. Roundworms are invertebrates in Phylum Nematoda. This is a very diverse phylum. It has more than 80,000 known species. Roundworms range in length from less than 1 millimeter to over 7 meters in length. You can see an example of a roundworm in Figure 12.13. Roundworms have a round body because they have a partial fluid-filled body cavity (pseudocoelom). This is one way that roundworms differ from flatworms. Another way is their complete digestive system. It allows them to eat, digest food, and eliminate wastes all at the same time. Roundworms have a tough covering of cuticle on the surface of their body. It prevents their body from expanding. This allows the buildup of fluid pressure in their partial body cavity. The fluid pressure adds stiffness to the body. This provides a counterforce for the contraction of muscles, allowing roundworms to move easily over surfaces. Roundworms reproduce sexually. Sperm and eggs are produced by separate male and female adults. Fertilization takes place inside the female organism. Females lay huge numbers of eggs, sometimes as many as 100,000 per day! The eggs hatch into larvae, which develop into adults. Then the life cycle repeats. Roundworms may be free-living or parasitic organisms. Free-living worms are found mainly in freshwater habitats. Some live in moist soil. They generally feed on bacteria, fungi, protozoa, or decaying organic matter. By breaking down organic matter, they play an important role in the carbon cycle. Parasitic roundworms may have plant, invertebrate, or vertebrate hosts. Several roundworm species infect humans. Besides ascaris, they include hookworms. Hookworms are named for the hooks they use to grab onto the hosts intestines. You can see the hooks in Figure 12.14. Hookworm larvae enter the host through the skin. They migrate to the intestine, where they mature into adults. Female adults lay large quantities of eggs. Eggs pass out of the host in feces. Eggs hatch into larvae in the feces or soil. Then the cycle repeats. You can learn more about parasitic roundworms in humans by watching this short video: . MEDIA Click image to the left or use the URL below. URL:
|
A roundworms body is stiff because of
|
[
"fluid pressure"
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Flatworms are invertebrates that belong to Phylum Platyhelminthes. There are more than 25,000 species in the flatworm phylum. Not all flatworms are as long as tapeworms. Some are only about a millimeter in length. Flatworms have a flat body because they lack a fluid-filled body cavity. They also have an incomplete digestive system with a single opening. However, flatworms represent several evolutionary advances in invertebrates. They have the following adaptations: Flatworms have three embryonic cell layers. They have a mesoderm layer in addition to ectoderm and endoderm layers. The mesoderm layer allows flatworms to develop muscle tissues so they can move easily over solid surfaces. Flatworms have a concentration of nerve tissue in the head end. This was a major step in the evolution of a brain. It was also needed for bilateral symmetry. Flatworms have bilateral symmetry. This gives them a better sense of direction than radial symmetry would. Watch this amazing flatworm video to learn about some of the other firsts these simple animals achieved, including being the first hunters: http://shapeoflife.org/video/flatworms-first-hunter MEDIA Click image to the left or use the URL below. URL: Flatworms reproduce sexually. In most species, the same individuals produce both eggs and sperm. After fertilization occurs, the fertilized eggs pass out of the adults body and hatch into larvae. There may be several different larval stages. The final larval stage develops into the adult form. Then the life cycle repeats. Some flatworms live in water or moist soil. They eat invertebrates and decaying animals. Other flatworms, such as tapeworms, are parasites that live inside vertebrate hosts. Usually, more than one type of host is needed to complete the parasites life cycle, as shown in Figure 12.12. Roundworms are invertebrates in Phylum Nematoda. This is a very diverse phylum. It has more than 80,000 known species. Roundworms range in length from less than 1 millimeter to over 7 meters in length. You can see an example of a roundworm in Figure 12.13. Roundworms have a round body because they have a partial fluid-filled body cavity (pseudocoelom). This is one way that roundworms differ from flatworms. Another way is their complete digestive system. It allows them to eat, digest food, and eliminate wastes all at the same time. Roundworms have a tough covering of cuticle on the surface of their body. It prevents their body from expanding. This allows the buildup of fluid pressure in their partial body cavity. The fluid pressure adds stiffness to the body. This provides a counterforce for the contraction of muscles, allowing roundworms to move easily over surfaces. Roundworms reproduce sexually. Sperm and eggs are produced by separate male and female adults. Fertilization takes place inside the female organism. Females lay huge numbers of eggs, sometimes as many as 100,000 per day! The eggs hatch into larvae, which develop into adults. Then the life cycle repeats. Roundworms may be free-living or parasitic organisms. Free-living worms are found mainly in freshwater habitats. Some live in moist soil. They generally feed on bacteria, fungi, protozoa, or decaying organic matter. By breaking down organic matter, they play an important role in the carbon cycle. Parasitic roundworms may have plant, invertebrate, or vertebrate hosts. Several roundworm species infect humans. Besides ascaris, they include hookworms. Hookworms are named for the hooks they use to grab onto the hosts intestines. You can see the hooks in Figure 12.14. Hookworm larvae enter the host through the skin. They migrate to the intestine, where they mature into adults. Female adults lay large quantities of eggs. Eggs pass out of the host in feces. Eggs hatch into larvae in the feces or soil. Then the cycle repeats. You can learn more about parasitic roundworms in humans by watching this short video: . MEDIA Click image to the left or use the URL below. URL:
|
How many eggs can a single roundworm lay in a day?
|
[
"as many as 100,000"
] |
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Flatworms are invertebrates that belong to Phylum Platyhelminthes. There are more than 25,000 species in the flatworm phylum. Not all flatworms are as long as tapeworms. Some are only about a millimeter in length. Flatworms have a flat body because they lack a fluid-filled body cavity. They also have an incomplete digestive system with a single opening. However, flatworms represent several evolutionary advances in invertebrates. They have the following adaptations: Flatworms have three embryonic cell layers. They have a mesoderm layer in addition to ectoderm and endoderm layers. The mesoderm layer allows flatworms to develop muscle tissues so they can move easily over solid surfaces. Flatworms have a concentration of nerve tissue in the head end. This was a major step in the evolution of a brain. It was also needed for bilateral symmetry. Flatworms have bilateral symmetry. This gives them a better sense of direction than radial symmetry would. Watch this amazing flatworm video to learn about some of the other firsts these simple animals achieved, including being the first hunters: http://shapeoflife.org/video/flatworms-first-hunter MEDIA Click image to the left or use the URL below. URL: Flatworms reproduce sexually. In most species, the same individuals produce both eggs and sperm. After fertilization occurs, the fertilized eggs pass out of the adults body and hatch into larvae. There may be several different larval stages. The final larval stage develops into the adult form. Then the life cycle repeats. Some flatworms live in water or moist soil. They eat invertebrates and decaying animals. Other flatworms, such as tapeworms, are parasites that live inside vertebrate hosts. Usually, more than one type of host is needed to complete the parasites life cycle, as shown in Figure 12.12. Roundworms are invertebrates in Phylum Nematoda. This is a very diverse phylum. It has more than 80,000 known species. Roundworms range in length from less than 1 millimeter to over 7 meters in length. You can see an example of a roundworm in Figure 12.13. Roundworms have a round body because they have a partial fluid-filled body cavity (pseudocoelom). This is one way that roundworms differ from flatworms. Another way is their complete digestive system. It allows them to eat, digest food, and eliminate wastes all at the same time. Roundworms have a tough covering of cuticle on the surface of their body. It prevents their body from expanding. This allows the buildup of fluid pressure in their partial body cavity. The fluid pressure adds stiffness to the body. This provides a counterforce for the contraction of muscles, allowing roundworms to move easily over surfaces. Roundworms reproduce sexually. Sperm and eggs are produced by separate male and female adults. Fertilization takes place inside the female organism. Females lay huge numbers of eggs, sometimes as many as 100,000 per day! The eggs hatch into larvae, which develop into adults. Then the life cycle repeats. Roundworms may be free-living or parasitic organisms. Free-living worms are found mainly in freshwater habitats. Some live in moist soil. They generally feed on bacteria, fungi, protozoa, or decaying organic matter. By breaking down organic matter, they play an important role in the carbon cycle. Parasitic roundworms may have plant, invertebrate, or vertebrate hosts. Several roundworm species infect humans. Besides ascaris, they include hookworms. Hookworms are named for the hooks they use to grab onto the hosts intestines. You can see the hooks in Figure 12.14. Hookworm larvae enter the host through the skin. They migrate to the intestine, where they mature into adults. Female adults lay large quantities of eggs. Eggs pass out of the host in feces. Eggs hatch into larvae in the feces or soil. Then the cycle repeats. You can learn more about parasitic roundworms in humans by watching this short video: . MEDIA Click image to the left or use the URL below. URL:
|
___common name for the type of worm that has a pseudocoelom
|
[
"roundworm"
] |
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Flatworms are invertebrates that belong to Phylum Platyhelminthes. There are more than 25,000 species in the flatworm phylum. Not all flatworms are as long as tapeworms. Some are only about a millimeter in length. Flatworms have a flat body because they lack a fluid-filled body cavity. They also have an incomplete digestive system with a single opening. However, flatworms represent several evolutionary advances in invertebrates. They have the following adaptations: Flatworms have three embryonic cell layers. They have a mesoderm layer in addition to ectoderm and endoderm layers. The mesoderm layer allows flatworms to develop muscle tissues so they can move easily over solid surfaces. Flatworms have a concentration of nerve tissue in the head end. This was a major step in the evolution of a brain. It was also needed for bilateral symmetry. Flatworms have bilateral symmetry. This gives them a better sense of direction than radial symmetry would. Watch this amazing flatworm video to learn about some of the other firsts these simple animals achieved, including being the first hunters: http://shapeoflife.org/video/flatworms-first-hunter MEDIA Click image to the left or use the URL below. URL: Flatworms reproduce sexually. In most species, the same individuals produce both eggs and sperm. After fertilization occurs, the fertilized eggs pass out of the adults body and hatch into larvae. There may be several different larval stages. The final larval stage develops into the adult form. Then the life cycle repeats. Some flatworms live in water or moist soil. They eat invertebrates and decaying animals. Other flatworms, such as tapeworms, are parasites that live inside vertebrate hosts. Usually, more than one type of host is needed to complete the parasites life cycle, as shown in Figure 12.12. Roundworms are invertebrates in Phylum Nematoda. This is a very diverse phylum. It has more than 80,000 known species. Roundworms range in length from less than 1 millimeter to over 7 meters in length. You can see an example of a roundworm in Figure 12.13. Roundworms have a round body because they have a partial fluid-filled body cavity (pseudocoelom). This is one way that roundworms differ from flatworms. Another way is their complete digestive system. It allows them to eat, digest food, and eliminate wastes all at the same time. Roundworms have a tough covering of cuticle on the surface of their body. It prevents their body from expanding. This allows the buildup of fluid pressure in their partial body cavity. The fluid pressure adds stiffness to the body. This provides a counterforce for the contraction of muscles, allowing roundworms to move easily over surfaces. Roundworms reproduce sexually. Sperm and eggs are produced by separate male and female adults. Fertilization takes place inside the female organism. Females lay huge numbers of eggs, sometimes as many as 100,000 per day! The eggs hatch into larvae, which develop into adults. Then the life cycle repeats. Roundworms may be free-living or parasitic organisms. Free-living worms are found mainly in freshwater habitats. Some live in moist soil. They generally feed on bacteria, fungi, protozoa, or decaying organic matter. By breaking down organic matter, they play an important role in the carbon cycle. Parasitic roundworms may have plant, invertebrate, or vertebrate hosts. Several roundworm species infect humans. Besides ascaris, they include hookworms. Hookworms are named for the hooks they use to grab onto the hosts intestines. You can see the hooks in Figure 12.14. Hookworm larvae enter the host through the skin. They migrate to the intestine, where they mature into adults. Female adults lay large quantities of eggs. Eggs pass out of the host in feces. Eggs hatch into larvae in the feces or soil. Then the cycle repeats. You can learn more about parasitic roundworms in humans by watching this short video: . MEDIA Click image to the left or use the URL below. URL:
|
___name of the phylum to which roundworms belong
|
[
"Nematoda"
] |
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Flatworms are invertebrates that belong to Phylum Platyhelminthes. There are more than 25,000 species in the flatworm phylum. Not all flatworms are as long as tapeworms. Some are only about a millimeter in length. Flatworms have a flat body because they lack a fluid-filled body cavity. They also have an incomplete digestive system with a single opening. However, flatworms represent several evolutionary advances in invertebrates. They have the following adaptations: Flatworms have three embryonic cell layers. They have a mesoderm layer in addition to ectoderm and endoderm layers. The mesoderm layer allows flatworms to develop muscle tissues so they can move easily over solid surfaces. Flatworms have a concentration of nerve tissue in the head end. This was a major step in the evolution of a brain. It was also needed for bilateral symmetry. Flatworms have bilateral symmetry. This gives them a better sense of direction than radial symmetry would. Watch this amazing flatworm video to learn about some of the other firsts these simple animals achieved, including being the first hunters: http://shapeoflife.org/video/flatworms-first-hunter MEDIA Click image to the left or use the URL below. URL: Flatworms reproduce sexually. In most species, the same individuals produce both eggs and sperm. After fertilization occurs, the fertilized eggs pass out of the adults body and hatch into larvae. There may be several different larval stages. The final larval stage develops into the adult form. Then the life cycle repeats. Some flatworms live in water or moist soil. They eat invertebrates and decaying animals. Other flatworms, such as tapeworms, are parasites that live inside vertebrate hosts. Usually, more than one type of host is needed to complete the parasites life cycle, as shown in Figure 12.12. Roundworms are invertebrates in Phylum Nematoda. This is a very diverse phylum. It has more than 80,000 known species. Roundworms range in length from less than 1 millimeter to over 7 meters in length. You can see an example of a roundworm in Figure 12.13. Roundworms have a round body because they have a partial fluid-filled body cavity (pseudocoelom). This is one way that roundworms differ from flatworms. Another way is their complete digestive system. It allows them to eat, digest food, and eliminate wastes all at the same time. Roundworms have a tough covering of cuticle on the surface of their body. It prevents their body from expanding. This allows the buildup of fluid pressure in their partial body cavity. The fluid pressure adds stiffness to the body. This provides a counterforce for the contraction of muscles, allowing roundworms to move easily over surfaces. Roundworms reproduce sexually. Sperm and eggs are produced by separate male and female adults. Fertilization takes place inside the female organism. Females lay huge numbers of eggs, sometimes as many as 100,000 per day! The eggs hatch into larvae, which develop into adults. Then the life cycle repeats. Roundworms may be free-living or parasitic organisms. Free-living worms are found mainly in freshwater habitats. Some live in moist soil. They generally feed on bacteria, fungi, protozoa, or decaying organic matter. By breaking down organic matter, they play an important role in the carbon cycle. Parasitic roundworms may have plant, invertebrate, or vertebrate hosts. Several roundworm species infect humans. Besides ascaris, they include hookworms. Hookworms are named for the hooks they use to grab onto the hosts intestines. You can see the hooks in Figure 12.14. Hookworm larvae enter the host through the skin. They migrate to the intestine, where they mature into adults. Female adults lay large quantities of eggs. Eggs pass out of the host in feces. Eggs hatch into larvae in the feces or soil. Then the cycle repeats. You can learn more about parasitic roundworms in humans by watching this short video: . MEDIA Click image to the left or use the URL below. URL:
|
___parasitic roundworm with special structures for attaching to the hosts intestines
|
[
"hookworm"
] |
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Flatworms are invertebrates that belong to Phylum Platyhelminthes. There are more than 25,000 species in the flatworm phylum. Not all flatworms are as long as tapeworms. Some are only about a millimeter in length. Flatworms have a flat body because they lack a fluid-filled body cavity. They also have an incomplete digestive system with a single opening. However, flatworms represent several evolutionary advances in invertebrates. They have the following adaptations: Flatworms have three embryonic cell layers. They have a mesoderm layer in addition to ectoderm and endoderm layers. The mesoderm layer allows flatworms to develop muscle tissues so they can move easily over solid surfaces. Flatworms have a concentration of nerve tissue in the head end. This was a major step in the evolution of a brain. It was also needed for bilateral symmetry. Flatworms have bilateral symmetry. This gives them a better sense of direction than radial symmetry would. Watch this amazing flatworm video to learn about some of the other firsts these simple animals achieved, including being the first hunters: http://shapeoflife.org/video/flatworms-first-hunter MEDIA Click image to the left or use the URL below. URL: Flatworms reproduce sexually. In most species, the same individuals produce both eggs and sperm. After fertilization occurs, the fertilized eggs pass out of the adults body and hatch into larvae. There may be several different larval stages. The final larval stage develops into the adult form. Then the life cycle repeats. Some flatworms live in water or moist soil. They eat invertebrates and decaying animals. Other flatworms, such as tapeworms, are parasites that live inside vertebrate hosts. Usually, more than one type of host is needed to complete the parasites life cycle, as shown in Figure 12.12. Roundworms are invertebrates in Phylum Nematoda. This is a very diverse phylum. It has more than 80,000 known species. Roundworms range in length from less than 1 millimeter to over 7 meters in length. You can see an example of a roundworm in Figure 12.13. Roundworms have a round body because they have a partial fluid-filled body cavity (pseudocoelom). This is one way that roundworms differ from flatworms. Another way is their complete digestive system. It allows them to eat, digest food, and eliminate wastes all at the same time. Roundworms have a tough covering of cuticle on the surface of their body. It prevents their body from expanding. This allows the buildup of fluid pressure in their partial body cavity. The fluid pressure adds stiffness to the body. This provides a counterforce for the contraction of muscles, allowing roundworms to move easily over surfaces. Roundworms reproduce sexually. Sperm and eggs are produced by separate male and female adults. Fertilization takes place inside the female organism. Females lay huge numbers of eggs, sometimes as many as 100,000 per day! The eggs hatch into larvae, which develop into adults. Then the life cycle repeats. Roundworms may be free-living or parasitic organisms. Free-living worms are found mainly in freshwater habitats. Some live in moist soil. They generally feed on bacteria, fungi, protozoa, or decaying organic matter. By breaking down organic matter, they play an important role in the carbon cycle. Parasitic roundworms may have plant, invertebrate, or vertebrate hosts. Several roundworm species infect humans. Besides ascaris, they include hookworms. Hookworms are named for the hooks they use to grab onto the hosts intestines. You can see the hooks in Figure 12.14. Hookworm larvae enter the host through the skin. They migrate to the intestine, where they mature into adults. Female adults lay large quantities of eggs. Eggs pass out of the host in feces. Eggs hatch into larvae in the feces or soil. Then the cycle repeats. You can learn more about parasitic roundworms in humans by watching this short video: . MEDIA Click image to the left or use the URL below. URL:
|
___common name for the type of worm that lacks a pseudocoelom
|
[
"flatworm"
] |
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Flatworms are invertebrates that belong to Phylum Platyhelminthes. There are more than 25,000 species in the flatworm phylum. Not all flatworms are as long as tapeworms. Some are only about a millimeter in length. Flatworms have a flat body because they lack a fluid-filled body cavity. They also have an incomplete digestive system with a single opening. However, flatworms represent several evolutionary advances in invertebrates. They have the following adaptations: Flatworms have three embryonic cell layers. They have a mesoderm layer in addition to ectoderm and endoderm layers. The mesoderm layer allows flatworms to develop muscle tissues so they can move easily over solid surfaces. Flatworms have a concentration of nerve tissue in the head end. This was a major step in the evolution of a brain. It was also needed for bilateral symmetry. Flatworms have bilateral symmetry. This gives them a better sense of direction than radial symmetry would. Watch this amazing flatworm video to learn about some of the other firsts these simple animals achieved, including being the first hunters: http://shapeoflife.org/video/flatworms-first-hunter MEDIA Click image to the left or use the URL below. URL: Flatworms reproduce sexually. In most species, the same individuals produce both eggs and sperm. After fertilization occurs, the fertilized eggs pass out of the adults body and hatch into larvae. There may be several different larval stages. The final larval stage develops into the adult form. Then the life cycle repeats. Some flatworms live in water or moist soil. They eat invertebrates and decaying animals. Other flatworms, such as tapeworms, are parasites that live inside vertebrate hosts. Usually, more than one type of host is needed to complete the parasites life cycle, as shown in Figure 12.12. Roundworms are invertebrates in Phylum Nematoda. This is a very diverse phylum. It has more than 80,000 known species. Roundworms range in length from less than 1 millimeter to over 7 meters in length. You can see an example of a roundworm in Figure 12.13. Roundworms have a round body because they have a partial fluid-filled body cavity (pseudocoelom). This is one way that roundworms differ from flatworms. Another way is their complete digestive system. It allows them to eat, digest food, and eliminate wastes all at the same time. Roundworms have a tough covering of cuticle on the surface of their body. It prevents their body from expanding. This allows the buildup of fluid pressure in their partial body cavity. The fluid pressure adds stiffness to the body. This provides a counterforce for the contraction of muscles, allowing roundworms to move easily over surfaces. Roundworms reproduce sexually. Sperm and eggs are produced by separate male and female adults. Fertilization takes place inside the female organism. Females lay huge numbers of eggs, sometimes as many as 100,000 per day! The eggs hatch into larvae, which develop into adults. Then the life cycle repeats. Roundworms may be free-living or parasitic organisms. Free-living worms are found mainly in freshwater habitats. Some live in moist soil. They generally feed on bacteria, fungi, protozoa, or decaying organic matter. By breaking down organic matter, they play an important role in the carbon cycle. Parasitic roundworms may have plant, invertebrate, or vertebrate hosts. Several roundworm species infect humans. Besides ascaris, they include hookworms. Hookworms are named for the hooks they use to grab onto the hosts intestines. You can see the hooks in Figure 12.14. Hookworm larvae enter the host through the skin. They migrate to the intestine, where they mature into adults. Female adults lay large quantities of eggs. Eggs pass out of the host in feces. Eggs hatch into larvae in the feces or soil. Then the cycle repeats. You can learn more about parasitic roundworms in humans by watching this short video: . MEDIA Click image to the left or use the URL below. URL:
|
___name of the phylum to which flatworms belong
|
[
"Platyhelminthes"
] |
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|
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Flatworms are invertebrates that belong to Phylum Platyhelminthes. There are more than 25,000 species in the flatworm phylum. Not all flatworms are as long as tapeworms. Some are only about a millimeter in length. Flatworms have a flat body because they lack a fluid-filled body cavity. They also have an incomplete digestive system with a single opening. However, flatworms represent several evolutionary advances in invertebrates. They have the following adaptations: Flatworms have three embryonic cell layers. They have a mesoderm layer in addition to ectoderm and endoderm layers. The mesoderm layer allows flatworms to develop muscle tissues so they can move easily over solid surfaces. Flatworms have a concentration of nerve tissue in the head end. This was a major step in the evolution of a brain. It was also needed for bilateral symmetry. Flatworms have bilateral symmetry. This gives them a better sense of direction than radial symmetry would. Watch this amazing flatworm video to learn about some of the other firsts these simple animals achieved, including being the first hunters: http://shapeoflife.org/video/flatworms-first-hunter MEDIA Click image to the left or use the URL below. URL: Flatworms reproduce sexually. In most species, the same individuals produce both eggs and sperm. After fertilization occurs, the fertilized eggs pass out of the adults body and hatch into larvae. There may be several different larval stages. The final larval stage develops into the adult form. Then the life cycle repeats. Some flatworms live in water or moist soil. They eat invertebrates and decaying animals. Other flatworms, such as tapeworms, are parasites that live inside vertebrate hosts. Usually, more than one type of host is needed to complete the parasites life cycle, as shown in Figure 12.12. Roundworms are invertebrates in Phylum Nematoda. This is a very diverse phylum. It has more than 80,000 known species. Roundworms range in length from less than 1 millimeter to over 7 meters in length. You can see an example of a roundworm in Figure 12.13. Roundworms have a round body because they have a partial fluid-filled body cavity (pseudocoelom). This is one way that roundworms differ from flatworms. Another way is their complete digestive system. It allows them to eat, digest food, and eliminate wastes all at the same time. Roundworms have a tough covering of cuticle on the surface of their body. It prevents their body from expanding. This allows the buildup of fluid pressure in their partial body cavity. The fluid pressure adds stiffness to the body. This provides a counterforce for the contraction of muscles, allowing roundworms to move easily over surfaces. Roundworms reproduce sexually. Sperm and eggs are produced by separate male and female adults. Fertilization takes place inside the female organism. Females lay huge numbers of eggs, sometimes as many as 100,000 per day! The eggs hatch into larvae, which develop into adults. Then the life cycle repeats. Roundworms may be free-living or parasitic organisms. Free-living worms are found mainly in freshwater habitats. Some live in moist soil. They generally feed on bacteria, fungi, protozoa, or decaying organic matter. By breaking down organic matter, they play an important role in the carbon cycle. Parasitic roundworms may have plant, invertebrate, or vertebrate hosts. Several roundworm species infect humans. Besides ascaris, they include hookworms. Hookworms are named for the hooks they use to grab onto the hosts intestines. You can see the hooks in Figure 12.14. Hookworm larvae enter the host through the skin. They migrate to the intestine, where they mature into adults. Female adults lay large quantities of eggs. Eggs pass out of the host in feces. Eggs hatch into larvae in the feces or soil. Then the cycle repeats. You can learn more about parasitic roundworms in humans by watching this short video: . MEDIA Click image to the left or use the URL below. URL:
|
___largest and most common parasitic worm in humans
|
[
"ascaris"
] |
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|
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A biochemical compound is any carbon-based compound found in living things. Like hydrocarbons, all biochemi- cal compounds contain hydrogen as well as carbon. However, biochemical compounds also contain other elements, such as oxygen and nitrogen. Almost all biochemical compounds are polymers. They consist of many, smaller monomer molecules. Biochemical polymers are referred to as macromolecules. The prefix macro means "large," and many biochemical molecules are very large indeed. They may contain thousands of monomer molecules. Biochemical compounds make up the cells and tissues of organisms. They are also involved in life processes, such as making and using food for energy. Given their diversity of functions, its not surprising that there are millions of different biochemical compounds. However, they can be grouped into just four main classes: carbohydrates, proteins, lipids, and nucleic acids. The classes are summarized in Table 9.3 and described in the rest of this lesson. Class Carbohydrates Elements carbon hydrogen oxygen Examples sugars starches cellulose Proteins carbon hydrogen oxygen nitrogen sulfur carbon hydrogen oxygen carbon hydrogen oxygen nitrogen phosphorus enzymes hormones Lipids Nucleic acids Functions provide energy to cells store energy in plants makes up the cell walls of plants speed up biochemical re- actions regulate life processes fats oils store energy in animals store energy in plants DNA RNA stores genetic information in cells helps cells make proteins Carbohydrates are biochemical compounds that include sugars, starches, and cellulose. They contain oxygen in addition to carbon and hydrogen. Organisms use carbohydrates mainly for energy. Sugars are simple carbohydrates. Molecules of sugar have just a few carbon atoms. The simplest sugar is glucose (C6 H12 O6 ). Glucose is the sugar that the cells of living things use for energy. Plants and some other organisms make glucose in the process of photosynthesis. Living things that cannot make glucose obtain it by consuming plants or these other organisms. You can see the structural formula of glucose and two other sugars in Figure 9.16. The other sugars in the figure are fructose and sucrose. Fructose is an isomer of glucose. It is found in fruits. It has the same atoms as glucose, but they are arranged differently. Sucrose is table sugar. It consists of one molecule of glucose and one molecule of fructose. Starches are complex carbohydrates. They are polymers of glucose. They consist of hundreds of glucose monomers bonded together. Plants make starch to store extra sugars. Consumers get starch from plants. Common sources of starch in the human diet are pictured in Figure 9.17. Our digestive system breaks down starch to simple sugars, which our cells use for energy. Cellulose is another complex carbohydrate that is a polymer of glucose. However, the glucose molecules are bonded together differently in cellulose than they are in starches. Cellulose molecules bundle together to form long, tough fibers (see Figure 9.18). Have you ever eaten raw celery? If you have, then you probably noticed that the stalks contain long, stringy fibers. The fibers are mostly cellulose. Cellulose is the most abundant biochemical compound. It makes up the cell walls of plants and gives support to trunks and stems. Cellulose also provides needed fiber in the human diet. We cant digest cellulose, but it helps keep food wastes moving through the digestive tract. Proteins are biochemical compounds that contain oxygen, nitrogen, and sulfur in addition to carbon and hydrogen. Protein molecules consist of one or more chains of small molecules called amino acids. Amino acids are the "building blocks" of proteins. There are 20 different common amino acids. The structural formula of the simplest amino acid, called glycine, is shown in Figure 9.19. Other amino acids have a similar structure. The sequence of amino acids and the number of amino acid chains in a protein determine the proteins shape. The shape of a protein, in turn, determines its function. Shapes may be very complex. You can learn more about the structure of proteins at the URL below. MEDIA Click image to the left or use the URL below. URL: Proteins are the most common biochemicals. They have many different functions, including: making up tissues as components of muscle. speeding up biochemical reactions as enzymes. regulating life
|
class of biochemical compounds that includes oils
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A biochemical compound is any carbon-based compound found in living things. Like hydrocarbons, all biochemi- cal compounds contain hydrogen as well as carbon. However, biochemical compounds also contain other elements, such as oxygen and nitrogen. Almost all biochemical compounds are polymers. They consist of many, smaller monomer molecules. Biochemical polymers are referred to as macromolecules. The prefix macro means "large," and many biochemical molecules are very large indeed. They may contain thousands of monomer molecules. Biochemical compounds make up the cells and tissues of organisms. They are also involved in life processes, such as making and using food for energy. Given their diversity of functions, its not surprising that there are millions of different biochemical compounds. However, they can be grouped into just four main classes: carbohydrates, proteins, lipids, and nucleic acids. The classes are summarized in Table 9.3 and described in the rest of this lesson. Class Carbohydrates Elements carbon hydrogen oxygen Examples sugars starches cellulose Proteins carbon hydrogen oxygen nitrogen sulfur carbon hydrogen oxygen carbon hydrogen oxygen nitrogen phosphorus enzymes hormones Lipids Nucleic acids Functions provide energy to cells store energy in plants makes up the cell walls of plants speed up biochemical re- actions regulate life processes fats oils store energy in animals store energy in plants DNA RNA stores genetic information in cells helps cells make proteins Carbohydrates are biochemical compounds that include sugars, starches, and cellulose. They contain oxygen in addition to carbon and hydrogen. Organisms use carbohydrates mainly for energy. Sugars are simple carbohydrates. Molecules of sugar have just a few carbon atoms. The simplest sugar is glucose (C6 H12 O6 ). Glucose is the sugar that the cells of living things use for energy. Plants and some other organisms make glucose in the process of photosynthesis. Living things that cannot make glucose obtain it by consuming plants or these other organisms. You can see the structural formula of glucose and two other sugars in Figure 9.16. The other sugars in the figure are fructose and sucrose. Fructose is an isomer of glucose. It is found in fruits. It has the same atoms as glucose, but they are arranged differently. Sucrose is table sugar. It consists of one molecule of glucose and one molecule of fructose. Starches are complex carbohydrates. They are polymers of glucose. They consist of hundreds of glucose monomers bonded together. Plants make starch to store extra sugars. Consumers get starch from plants. Common sources of starch in the human diet are pictured in Figure 9.17. Our digestive system breaks down starch to simple sugars, which our cells use for energy. Cellulose is another complex carbohydrate that is a polymer of glucose. However, the glucose molecules are bonded together differently in cellulose than they are in starches. Cellulose molecules bundle together to form long, tough fibers (see Figure 9.18). Have you ever eaten raw celery? If you have, then you probably noticed that the stalks contain long, stringy fibers. The fibers are mostly cellulose. Cellulose is the most abundant biochemical compound. It makes up the cell walls of plants and gives support to trunks and stems. Cellulose also provides needed fiber in the human diet. We cant digest cellulose, but it helps keep food wastes moving through the digestive tract. Proteins are biochemical compounds that contain oxygen, nitrogen, and sulfur in addition to carbon and hydrogen. Protein molecules consist of one or more chains of small molecules called amino acids. Amino acids are the "building blocks" of proteins. There are 20 different common amino acids. The structural formula of the simplest amino acid, called glycine, is shown in Figure 9.19. Other amino acids have a similar structure. The sequence of amino acids and the number of amino acid chains in a protein determine the proteins shape. The shape of a protein, in turn, determines its function. Shapes may be very complex. You can learn more about the structure of proteins at the URL below. MEDIA Click image to the left or use the URL below. URL: Proteins are the most common biochemicals. They have many different functions, including: making up tissues as components of muscle. speeding up biochemical reactions as enzymes. regulating life
|
general name given to biochemical polymers
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A biochemical compound is any carbon-based compound found in living things. Like hydrocarbons, all biochemi- cal compounds contain hydrogen as well as carbon. However, biochemical compounds also contain other elements, such as oxygen and nitrogen. Almost all biochemical compounds are polymers. They consist of many, smaller monomer molecules. Biochemical polymers are referred to as macromolecules. The prefix macro means "large," and many biochemical molecules are very large indeed. They may contain thousands of monomer molecules. Biochemical compounds make up the cells and tissues of organisms. They are also involved in life processes, such as making and using food for energy. Given their diversity of functions, its not surprising that there are millions of different biochemical compounds. However, they can be grouped into just four main classes: carbohydrates, proteins, lipids, and nucleic acids. The classes are summarized in Table 9.3 and described in the rest of this lesson. Class Carbohydrates Elements carbon hydrogen oxygen Examples sugars starches cellulose Proteins carbon hydrogen oxygen nitrogen sulfur carbon hydrogen oxygen carbon hydrogen oxygen nitrogen phosphorus enzymes hormones Lipids Nucleic acids Functions provide energy to cells store energy in plants makes up the cell walls of plants speed up biochemical re- actions regulate life processes fats oils store energy in animals store energy in plants DNA RNA stores genetic information in cells helps cells make proteins Carbohydrates are biochemical compounds that include sugars, starches, and cellulose. They contain oxygen in addition to carbon and hydrogen. Organisms use carbohydrates mainly for energy. Sugars are simple carbohydrates. Molecules of sugar have just a few carbon atoms. The simplest sugar is glucose (C6 H12 O6 ). Glucose is the sugar that the cells of living things use for energy. Plants and some other organisms make glucose in the process of photosynthesis. Living things that cannot make glucose obtain it by consuming plants or these other organisms. You can see the structural formula of glucose and two other sugars in Figure 9.16. The other sugars in the figure are fructose and sucrose. Fructose is an isomer of glucose. It is found in fruits. It has the same atoms as glucose, but they are arranged differently. Sucrose is table sugar. It consists of one molecule of glucose and one molecule of fructose. Starches are complex carbohydrates. They are polymers of glucose. They consist of hundreds of glucose monomers bonded together. Plants make starch to store extra sugars. Consumers get starch from plants. Common sources of starch in the human diet are pictured in Figure 9.17. Our digestive system breaks down starch to simple sugars, which our cells use for energy. Cellulose is another complex carbohydrate that is a polymer of glucose. However, the glucose molecules are bonded together differently in cellulose than they are in starches. Cellulose molecules bundle together to form long, tough fibers (see Figure 9.18). Have you ever eaten raw celery? If you have, then you probably noticed that the stalks contain long, stringy fibers. The fibers are mostly cellulose. Cellulose is the most abundant biochemical compound. It makes up the cell walls of plants and gives support to trunks and stems. Cellulose also provides needed fiber in the human diet. We cant digest cellulose, but it helps keep food wastes moving through the digestive tract. Proteins are biochemical compounds that contain oxygen, nitrogen, and sulfur in addition to carbon and hydrogen. Protein molecules consist of one or more chains of small molecules called amino acids. Amino acids are the "building blocks" of proteins. There are 20 different common amino acids. The structural formula of the simplest amino acid, called glycine, is shown in Figure 9.19. Other amino acids have a similar structure. The sequence of amino acids and the number of amino acid chains in a protein determine the proteins shape. The shape of a protein, in turn, determines its function. Shapes may be very complex. You can learn more about the structure of proteins at the URL below. MEDIA Click image to the left or use the URL below. URL: Proteins are the most common biochemicals. They have many different functions, including: making up tissues as components of muscle. speeding up biochemical reactions as enzymes. regulating life
|
class of biochemical compounds that includes DNA
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A biochemical compound is any carbon-based compound found in living things. Like hydrocarbons, all biochemi- cal compounds contain hydrogen as well as carbon. However, biochemical compounds also contain other elements, such as oxygen and nitrogen. Almost all biochemical compounds are polymers. They consist of many, smaller monomer molecules. Biochemical polymers are referred to as macromolecules. The prefix macro means "large," and many biochemical molecules are very large indeed. They may contain thousands of monomer molecules. Biochemical compounds make up the cells and tissues of organisms. They are also involved in life processes, such as making and using food for energy. Given their diversity of functions, its not surprising that there are millions of different biochemical compounds. However, they can be grouped into just four main classes: carbohydrates, proteins, lipids, and nucleic acids. The classes are summarized in Table 9.3 and described in the rest of this lesson. Class Carbohydrates Elements carbon hydrogen oxygen Examples sugars starches cellulose Proteins carbon hydrogen oxygen nitrogen sulfur carbon hydrogen oxygen carbon hydrogen oxygen nitrogen phosphorus enzymes hormones Lipids Nucleic acids Functions provide energy to cells store energy in plants makes up the cell walls of plants speed up biochemical re- actions regulate life processes fats oils store energy in animals store energy in plants DNA RNA stores genetic information in cells helps cells make proteins Carbohydrates are biochemical compounds that include sugars, starches, and cellulose. They contain oxygen in addition to carbon and hydrogen. Organisms use carbohydrates mainly for energy. Sugars are simple carbohydrates. Molecules of sugar have just a few carbon atoms. The simplest sugar is glucose (C6 H12 O6 ). Glucose is the sugar that the cells of living things use for energy. Plants and some other organisms make glucose in the process of photosynthesis. Living things that cannot make glucose obtain it by consuming plants or these other organisms. You can see the structural formula of glucose and two other sugars in Figure 9.16. The other sugars in the figure are fructose and sucrose. Fructose is an isomer of glucose. It is found in fruits. It has the same atoms as glucose, but they are arranged differently. Sucrose is table sugar. It consists of one molecule of glucose and one molecule of fructose. Starches are complex carbohydrates. They are polymers of glucose. They consist of hundreds of glucose monomers bonded together. Plants make starch to store extra sugars. Consumers get starch from plants. Common sources of starch in the human diet are pictured in Figure 9.17. Our digestive system breaks down starch to simple sugars, which our cells use for energy. Cellulose is another complex carbohydrate that is a polymer of glucose. However, the glucose molecules are bonded together differently in cellulose than they are in starches. Cellulose molecules bundle together to form long, tough fibers (see Figure 9.18). Have you ever eaten raw celery? If you have, then you probably noticed that the stalks contain long, stringy fibers. The fibers are mostly cellulose. Cellulose is the most abundant biochemical compound. It makes up the cell walls of plants and gives support to trunks and stems. Cellulose also provides needed fiber in the human diet. We cant digest cellulose, but it helps keep food wastes moving through the digestive tract. Proteins are biochemical compounds that contain oxygen, nitrogen, and sulfur in addition to carbon and hydrogen. Protein molecules consist of one or more chains of small molecules called amino acids. Amino acids are the "building blocks" of proteins. There are 20 different common amino acids. The structural formula of the simplest amino acid, called glycine, is shown in Figure 9.19. Other amino acids have a similar structure. The sequence of amino acids and the number of amino acid chains in a protein determine the proteins shape. The shape of a protein, in turn, determines its function. Shapes may be very complex. You can learn more about the structure of proteins at the URL below. MEDIA Click image to the left or use the URL below. URL: Proteins are the most common biochemicals. They have many different functions, including: making up tissues as components of muscle. speeding up biochemical reactions as enzymes. regulating life
|
building blocks of proteins
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A biochemical compound is any carbon-based compound found in living things. Like hydrocarbons, all biochemi- cal compounds contain hydrogen as well as carbon. However, biochemical compounds also contain other elements, such as oxygen and nitrogen. Almost all biochemical compounds are polymers. They consist of many, smaller monomer molecules. Biochemical polymers are referred to as macromolecules. The prefix macro means "large," and many biochemical molecules are very large indeed. They may contain thousands of monomer molecules. Biochemical compounds make up the cells and tissues of organisms. They are also involved in life processes, such as making and using food for energy. Given their diversity of functions, its not surprising that there are millions of different biochemical compounds. However, they can be grouped into just four main classes: carbohydrates, proteins, lipids, and nucleic acids. The classes are summarized in Table 9.3 and described in the rest of this lesson. Class Carbohydrates Elements carbon hydrogen oxygen Examples sugars starches cellulose Proteins carbon hydrogen oxygen nitrogen sulfur carbon hydrogen oxygen carbon hydrogen oxygen nitrogen phosphorus enzymes hormones Lipids Nucleic acids Functions provide energy to cells store energy in plants makes up the cell walls of plants speed up biochemical re- actions regulate life processes fats oils store energy in animals store energy in plants DNA RNA stores genetic information in cells helps cells make proteins Carbohydrates are biochemical compounds that include sugars, starches, and cellulose. They contain oxygen in addition to carbon and hydrogen. Organisms use carbohydrates mainly for energy. Sugars are simple carbohydrates. Molecules of sugar have just a few carbon atoms. The simplest sugar is glucose (C6 H12 O6 ). Glucose is the sugar that the cells of living things use for energy. Plants and some other organisms make glucose in the process of photosynthesis. Living things that cannot make glucose obtain it by consuming plants or these other organisms. You can see the structural formula of glucose and two other sugars in Figure 9.16. The other sugars in the figure are fructose and sucrose. Fructose is an isomer of glucose. It is found in fruits. It has the same atoms as glucose, but they are arranged differently. Sucrose is table sugar. It consists of one molecule of glucose and one molecule of fructose. Starches are complex carbohydrates. They are polymers of glucose. They consist of hundreds of glucose monomers bonded together. Plants make starch to store extra sugars. Consumers get starch from plants. Common sources of starch in the human diet are pictured in Figure 9.17. Our digestive system breaks down starch to simple sugars, which our cells use for energy. Cellulose is another complex carbohydrate that is a polymer of glucose. However, the glucose molecules are bonded together differently in cellulose than they are in starches. Cellulose molecules bundle together to form long, tough fibers (see Figure 9.18). Have you ever eaten raw celery? If you have, then you probably noticed that the stalks contain long, stringy fibers. The fibers are mostly cellulose. Cellulose is the most abundant biochemical compound. It makes up the cell walls of plants and gives support to trunks and stems. Cellulose also provides needed fiber in the human diet. We cant digest cellulose, but it helps keep food wastes moving through the digestive tract. Proteins are biochemical compounds that contain oxygen, nitrogen, and sulfur in addition to carbon and hydrogen. Protein molecules consist of one or more chains of small molecules called amino acids. Amino acids are the "building blocks" of proteins. There are 20 different common amino acids. The structural formula of the simplest amino acid, called glycine, is shown in Figure 9.19. Other amino acids have a similar structure. The sequence of amino acids and the number of amino acid chains in a protein determine the proteins shape. The shape of a protein, in turn, determines its function. Shapes may be very complex. You can learn more about the structure of proteins at the URL below. MEDIA Click image to the left or use the URL below. URL: Proteins are the most common biochemicals. They have many different functions, including: making up tissues as components of muscle. speeding up biochemical reactions as enzymes. regulating life
|
class of biochemical compounds that includes enzymes
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A biochemical compound is any carbon-based compound found in living things. Like hydrocarbons, all biochemi- cal compounds contain hydrogen as well as carbon. However, biochemical compounds also contain other elements, such as oxygen and nitrogen. Almost all biochemical compounds are polymers. They consist of many, smaller monomer molecules. Biochemical polymers are referred to as macromolecules. The prefix macro means "large," and many biochemical molecules are very large indeed. They may contain thousands of monomer molecules. Biochemical compounds make up the cells and tissues of organisms. They are also involved in life processes, such as making and using food for energy. Given their diversity of functions, its not surprising that there are millions of different biochemical compounds. However, they can be grouped into just four main classes: carbohydrates, proteins, lipids, and nucleic acids. The classes are summarized in Table 9.3 and described in the rest of this lesson. Class Carbohydrates Elements carbon hydrogen oxygen Examples sugars starches cellulose Proteins carbon hydrogen oxygen nitrogen sulfur carbon hydrogen oxygen carbon hydrogen oxygen nitrogen phosphorus enzymes hormones Lipids Nucleic acids Functions provide energy to cells store energy in plants makes up the cell walls of plants speed up biochemical re- actions regulate life processes fats oils store energy in animals store energy in plants DNA RNA stores genetic information in cells helps cells make proteins Carbohydrates are biochemical compounds that include sugars, starches, and cellulose. They contain oxygen in addition to carbon and hydrogen. Organisms use carbohydrates mainly for energy. Sugars are simple carbohydrates. Molecules of sugar have just a few carbon atoms. The simplest sugar is glucose (C6 H12 O6 ). Glucose is the sugar that the cells of living things use for energy. Plants and some other organisms make glucose in the process of photosynthesis. Living things that cannot make glucose obtain it by consuming plants or these other organisms. You can see the structural formula of glucose and two other sugars in Figure 9.16. The other sugars in the figure are fructose and sucrose. Fructose is an isomer of glucose. It is found in fruits. It has the same atoms as glucose, but they are arranged differently. Sucrose is table sugar. It consists of one molecule of glucose and one molecule of fructose. Starches are complex carbohydrates. They are polymers of glucose. They consist of hundreds of glucose monomers bonded together. Plants make starch to store extra sugars. Consumers get starch from plants. Common sources of starch in the human diet are pictured in Figure 9.17. Our digestive system breaks down starch to simple sugars, which our cells use for energy. Cellulose is another complex carbohydrate that is a polymer of glucose. However, the glucose molecules are bonded together differently in cellulose than they are in starches. Cellulose molecules bundle together to form long, tough fibers (see Figure 9.18). Have you ever eaten raw celery? If you have, then you probably noticed that the stalks contain long, stringy fibers. The fibers are mostly cellulose. Cellulose is the most abundant biochemical compound. It makes up the cell walls of plants and gives support to trunks and stems. Cellulose also provides needed fiber in the human diet. We cant digest cellulose, but it helps keep food wastes moving through the digestive tract. Proteins are biochemical compounds that contain oxygen, nitrogen, and sulfur in addition to carbon and hydrogen. Protein molecules consist of one or more chains of small molecules called amino acids. Amino acids are the "building blocks" of proteins. There are 20 different common amino acids. The structural formula of the simplest amino acid, called glycine, is shown in Figure 9.19. Other amino acids have a similar structure. The sequence of amino acids and the number of amino acid chains in a protein determine the proteins shape. The shape of a protein, in turn, determines its function. Shapes may be very complex. You can learn more about the structure of proteins at the URL below. MEDIA Click image to the left or use the URL below. URL: Proteins are the most common biochemicals. They have many different functions, including: making up tissues as components of muscle. speeding up biochemical reactions as enzymes. regulating life
|
class of biochemical compounds that includes cellulose
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A biochemical compound is any carbon-based compound found in living things. Like hydrocarbons, all biochemi- cal compounds contain hydrogen as well as carbon. However, biochemical compounds also contain other elements, such as oxygen and nitrogen. Almost all biochemical compounds are polymers. They consist of many, smaller monomer molecules. Biochemical polymers are referred to as macromolecules. The prefix macro means "large," and many biochemical molecules are very large indeed. They may contain thousands of monomer molecules. Biochemical compounds make up the cells and tissues of organisms. They are also involved in life processes, such as making and using food for energy. Given their diversity of functions, its not surprising that there are millions of different biochemical compounds. However, they can be grouped into just four main classes: carbohydrates, proteins, lipids, and nucleic acids. The classes are summarized in Table 9.3 and described in the rest of this lesson. Class Carbohydrates Elements carbon hydrogen oxygen Examples sugars starches cellulose Proteins carbon hydrogen oxygen nitrogen sulfur carbon hydrogen oxygen carbon hydrogen oxygen nitrogen phosphorus enzymes hormones Lipids Nucleic acids Functions provide energy to cells store energy in plants makes up the cell walls of plants speed up biochemical re- actions regulate life processes fats oils store energy in animals store energy in plants DNA RNA stores genetic information in cells helps cells make proteins Carbohydrates are biochemical compounds that include sugars, starches, and cellulose. They contain oxygen in addition to carbon and hydrogen. Organisms use carbohydrates mainly for energy. Sugars are simple carbohydrates. Molecules of sugar have just a few carbon atoms. The simplest sugar is glucose (C6 H12 O6 ). Glucose is the sugar that the cells of living things use for energy. Plants and some other organisms make glucose in the process of photosynthesis. Living things that cannot make glucose obtain it by consuming plants or these other organisms. You can see the structural formula of glucose and two other sugars in Figure 9.16. The other sugars in the figure are fructose and sucrose. Fructose is an isomer of glucose. It is found in fruits. It has the same atoms as glucose, but they are arranged differently. Sucrose is table sugar. It consists of one molecule of glucose and one molecule of fructose. Starches are complex carbohydrates. They are polymers of glucose. They consist of hundreds of glucose monomers bonded together. Plants make starch to store extra sugars. Consumers get starch from plants. Common sources of starch in the human diet are pictured in Figure 9.17. Our digestive system breaks down starch to simple sugars, which our cells use for energy. Cellulose is another complex carbohydrate that is a polymer of glucose. However, the glucose molecules are bonded together differently in cellulose than they are in starches. Cellulose molecules bundle together to form long, tough fibers (see Figure 9.18). Have you ever eaten raw celery? If you have, then you probably noticed that the stalks contain long, stringy fibers. The fibers are mostly cellulose. Cellulose is the most abundant biochemical compound. It makes up the cell walls of plants and gives support to trunks and stems. Cellulose also provides needed fiber in the human diet. We cant digest cellulose, but it helps keep food wastes moving through the digestive tract. Proteins are biochemical compounds that contain oxygen, nitrogen, and sulfur in addition to carbon and hydrogen. Protein molecules consist of one or more chains of small molecules called amino acids. Amino acids are the "building blocks" of proteins. There are 20 different common amino acids. The structural formula of the simplest amino acid, called glycine, is shown in Figure 9.19. Other amino acids have a similar structure. The sequence of amino acids and the number of amino acid chains in a protein determine the proteins shape. The shape of a protein, in turn, determines its function. Shapes may be very complex. You can learn more about the structure of proteins at the URL below. MEDIA Click image to the left or use the URL below. URL: Proteins are the most common biochemicals. They have many different functions, including: making up tissues as components of muscle. speeding up biochemical reactions as enzymes. regulating life
|
All biochemical compounds include carbon, hydrogen, and
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A biochemical compound is any carbon-based compound found in living things. Like hydrocarbons, all biochemi- cal compounds contain hydrogen as well as carbon. However, biochemical compounds also contain other elements, such as oxygen and nitrogen. Almost all biochemical compounds are polymers. They consist of many, smaller monomer molecules. Biochemical polymers are referred to as macromolecules. The prefix macro means "large," and many biochemical molecules are very large indeed. They may contain thousands of monomer molecules. Biochemical compounds make up the cells and tissues of organisms. They are also involved in life processes, such as making and using food for energy. Given their diversity of functions, its not surprising that there are millions of different biochemical compounds. However, they can be grouped into just four main classes: carbohydrates, proteins, lipids, and nucleic acids. The classes are summarized in Table 9.3 and described in the rest of this lesson. Class Carbohydrates Elements carbon hydrogen oxygen Examples sugars starches cellulose Proteins carbon hydrogen oxygen nitrogen sulfur carbon hydrogen oxygen carbon hydrogen oxygen nitrogen phosphorus enzymes hormones Lipids Nucleic acids Functions provide energy to cells store energy in plants makes up the cell walls of plants speed up biochemical re- actions regulate life processes fats oils store energy in animals store energy in plants DNA RNA stores genetic information in cells helps cells make proteins Carbohydrates are biochemical compounds that include sugars, starches, and cellulose. They contain oxygen in addition to carbon and hydrogen. Organisms use carbohydrates mainly for energy. Sugars are simple carbohydrates. Molecules of sugar have just a few carbon atoms. The simplest sugar is glucose (C6 H12 O6 ). Glucose is the sugar that the cells of living things use for energy. Plants and some other organisms make glucose in the process of photosynthesis. Living things that cannot make glucose obtain it by consuming plants or these other organisms. You can see the structural formula of glucose and two other sugars in Figure 9.16. The other sugars in the figure are fructose and sucrose. Fructose is an isomer of glucose. It is found in fruits. It has the same atoms as glucose, but they are arranged differently. Sucrose is table sugar. It consists of one molecule of glucose and one molecule of fructose. Starches are complex carbohydrates. They are polymers of glucose. They consist of hundreds of glucose monomers bonded together. Plants make starch to store extra sugars. Consumers get starch from plants. Common sources of starch in the human diet are pictured in Figure 9.17. Our digestive system breaks down starch to simple sugars, which our cells use for energy. Cellulose is another complex carbohydrate that is a polymer of glucose. However, the glucose molecules are bonded together differently in cellulose than they are in starches. Cellulose molecules bundle together to form long, tough fibers (see Figure 9.18). Have you ever eaten raw celery? If you have, then you probably noticed that the stalks contain long, stringy fibers. The fibers are mostly cellulose. Cellulose is the most abundant biochemical compound. It makes up the cell walls of plants and gives support to trunks and stems. Cellulose also provides needed fiber in the human diet. We cant digest cellulose, but it helps keep food wastes moving through the digestive tract. Proteins are biochemical compounds that contain oxygen, nitrogen, and sulfur in addition to carbon and hydrogen. Protein molecules consist of one or more chains of small molecules called amino acids. Amino acids are the "building blocks" of proteins. There are 20 different common amino acids. The structural formula of the simplest amino acid, called glycine, is shown in Figure 9.19. Other amino acids have a similar structure. The sequence of amino acids and the number of amino acid chains in a protein determine the proteins shape. The shape of a protein, in turn, determines its function. Shapes may be very complex. You can learn more about the structure of proteins at the URL below. MEDIA Click image to the left or use the URL below. URL: Proteins are the most common biochemicals. They have many different functions, including: making up tissues as components of muscle. speeding up biochemical reactions as enzymes. regulating life
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Organisms use carbohydrates mainly for
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Fungi (fungus, singular) are relatively simple eukaryotic organisms. They are placed in their own kingdom, the Fungus Kingdom. Most fungi are multicellular organisms. These fungi are called molds. However, some fungi exist as single cells. These fungi are called yeasts. You can see examples of different types of fungi in Figure 9.7. For a funny, fast-paced overview of fungi, watch this video: . MEDIA Click image to the left or use the URL below. URL: For a long time, scientists classified fungi as members of the Plant Kingdom. Fungi share several obvious traits with plants. For example, both fungi and plants lack the ability to move. Both grow in soil, and both have cell walls. Some fungi even look like plants. Today, fungi are no longer classified as plants. We now know that they have important traits that set them apart from plants. Thats why they are placed in their own kingdom. How do fungi differ from plants? The cell walls of fungi are made of chitin. Chitin is a tough carbohydrate that also makes up the outer skeleton of insects. The cell walls of plants are made of cellulose. Fungi are heterotrophs that absorb food from other organisms. Plants are autotrophs that make their own food. The Fungus Kingdom is large and diverse. It may contain more than a million species. However, fewer than 100,000 species of fungi have been identified. The earliest fungi evolved about 600 million years ago. They lived in the water. Fungi colonized the land around the same time as plants. That was probably between 400 and 500 million years ago. After that, fungi became very abundant on land. By 250 million years ago, they may have been the dominant life forms on land. Yeasts grow as single cells. Other fungi grow into multicellular, thread-like structures. These structures are called hyphae (hypha, singular). You can see a photo of hyphae in Figure 9.8. They resemble plant roots. Each hypha consists of a group of cells surrounded by a tubular cell wall. A mass of hyphae make up the body of a fungus. The body is called the mycelium (mycelia, plural). A mycelium may range in size from microscopic to very large. In fact, the largest living thing on Earth is the mycelium of a single fungus. Nicknamed the humongous fungus, it grows in a forest in Oregon. A small part of the fungus is pictured in Figure 9.9. The giant fungus covers an area of 2384 acres. Thats about the size of 1,665 football fields! The fungus is estimated to be at least 2400 years old, but it could be much older. Most fungi reproduce both asexually and sexually. In both types of reproduction, they produce spores. A spore is a special reproductive cell. When fungi reproduce asexually, they can spread quickly. This is good when conditions are stable. They can increase their genetic variation by sexual reproduction. This is beneficial when conditions are changing. Variation helps ensure that at least some organisms survive the changing conditions. Figure 9.10 shows how asexual and sexual reproduction occur in fungi. Refer to the figure as you read about each of them below. During asexual reproduction, fungi produce haploid spores by mitosis of a haploid parent cell. A haploid cell has just one of each pair of chromosomes. The haploid spores are genetically identical to the parent cell. Spores may be spread by moving water, wind, or other organisms. Wherever the spores land, they will develop into new hyphae only when conditions are suitable for growth. Yeasts are an exception. They reproduce asexually by budding instead of by producing spores. An offspring cell forms on a parent cell. After it grows and develops, it buds off to form a new cell. The offspring cell is genetically identical to the parent cell. You can see yeast cells budding in Figure 9.11. Sexual reproduction also occurs in most fungi. It happens when two haploid hyphae mate. During mating, two haploid parent cells fuse. The single fused cell that results is a diploid spore. It is genetically different from both parents.
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Fungi were originally classified as
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Fungi (fungus, singular) are relatively simple eukaryotic organisms. They are placed in their own kingdom, the Fungus Kingdom. Most fungi are multicellular organisms. These fungi are called molds. However, some fungi exist as single cells. These fungi are called yeasts. You can see examples of different types of fungi in Figure 9.7. For a funny, fast-paced overview of fungi, watch this video: . MEDIA Click image to the left or use the URL below. URL: For a long time, scientists classified fungi as members of the Plant Kingdom. Fungi share several obvious traits with plants. For example, both fungi and plants lack the ability to move. Both grow in soil, and both have cell walls. Some fungi even look like plants. Today, fungi are no longer classified as plants. We now know that they have important traits that set them apart from plants. Thats why they are placed in their own kingdom. How do fungi differ from plants? The cell walls of fungi are made of chitin. Chitin is a tough carbohydrate that also makes up the outer skeleton of insects. The cell walls of plants are made of cellulose. Fungi are heterotrophs that absorb food from other organisms. Plants are autotrophs that make their own food. The Fungus Kingdom is large and diverse. It may contain more than a million species. However, fewer than 100,000 species of fungi have been identified. The earliest fungi evolved about 600 million years ago. They lived in the water. Fungi colonized the land around the same time as plants. That was probably between 400 and 500 million years ago. After that, fungi became very abundant on land. By 250 million years ago, they may have been the dominant life forms on land. Yeasts grow as single cells. Other fungi grow into multicellular, thread-like structures. These structures are called hyphae (hypha, singular). You can see a photo of hyphae in Figure 9.8. They resemble plant roots. Each hypha consists of a group of cells surrounded by a tubular cell wall. A mass of hyphae make up the body of a fungus. The body is called the mycelium (mycelia, plural). A mycelium may range in size from microscopic to very large. In fact, the largest living thing on Earth is the mycelium of a single fungus. Nicknamed the humongous fungus, it grows in a forest in Oregon. A small part of the fungus is pictured in Figure 9.9. The giant fungus covers an area of 2384 acres. Thats about the size of 1,665 football fields! The fungus is estimated to be at least 2400 years old, but it could be much older. Most fungi reproduce both asexually and sexually. In both types of reproduction, they produce spores. A spore is a special reproductive cell. When fungi reproduce asexually, they can spread quickly. This is good when conditions are stable. They can increase their genetic variation by sexual reproduction. This is beneficial when conditions are changing. Variation helps ensure that at least some organisms survive the changing conditions. Figure 9.10 shows how asexual and sexual reproduction occur in fungi. Refer to the figure as you read about each of them below. During asexual reproduction, fungi produce haploid spores by mitosis of a haploid parent cell. A haploid cell has just one of each pair of chromosomes. The haploid spores are genetically identical to the parent cell. Spores may be spread by moving water, wind, or other organisms. Wherever the spores land, they will develop into new hyphae only when conditions are suitable for growth. Yeasts are an exception. They reproduce asexually by budding instead of by producing spores. An offspring cell forms on a parent cell. After it grows and develops, it buds off to form a new cell. The offspring cell is genetically identical to the parent cell. You can see yeast cells budding in Figure 9.11. Sexual reproduction also occurs in most fungi. It happens when two haploid hyphae mate. During mating, two haploid parent cells fuse. The single fused cell that results is a diploid spore. It is genetically different from both parents.
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All fungi are
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Fungi (fungus, singular) are relatively simple eukaryotic organisms. They are placed in their own kingdom, the Fungus Kingdom. Most fungi are multicellular organisms. These fungi are called molds. However, some fungi exist as single cells. These fungi are called yeasts. You can see examples of different types of fungi in Figure 9.7. For a funny, fast-paced overview of fungi, watch this video: . MEDIA Click image to the left or use the URL below. URL: For a long time, scientists classified fungi as members of the Plant Kingdom. Fungi share several obvious traits with plants. For example, both fungi and plants lack the ability to move. Both grow in soil, and both have cell walls. Some fungi even look like plants. Today, fungi are no longer classified as plants. We now know that they have important traits that set them apart from plants. Thats why they are placed in their own kingdom. How do fungi differ from plants? The cell walls of fungi are made of chitin. Chitin is a tough carbohydrate that also makes up the outer skeleton of insects. The cell walls of plants are made of cellulose. Fungi are heterotrophs that absorb food from other organisms. Plants are autotrophs that make their own food. The Fungus Kingdom is large and diverse. It may contain more than a million species. However, fewer than 100,000 species of fungi have been identified. The earliest fungi evolved about 600 million years ago. They lived in the water. Fungi colonized the land around the same time as plants. That was probably between 400 and 500 million years ago. After that, fungi became very abundant on land. By 250 million years ago, they may have been the dominant life forms on land. Yeasts grow as single cells. Other fungi grow into multicellular, thread-like structures. These structures are called hyphae (hypha, singular). You can see a photo of hyphae in Figure 9.8. They resemble plant roots. Each hypha consists of a group of cells surrounded by a tubular cell wall. A mass of hyphae make up the body of a fungus. The body is called the mycelium (mycelia, plural). A mycelium may range in size from microscopic to very large. In fact, the largest living thing on Earth is the mycelium of a single fungus. Nicknamed the humongous fungus, it grows in a forest in Oregon. A small part of the fungus is pictured in Figure 9.9. The giant fungus covers an area of 2384 acres. Thats about the size of 1,665 football fields! The fungus is estimated to be at least 2400 years old, but it could be much older. Most fungi reproduce both asexually and sexually. In both types of reproduction, they produce spores. A spore is a special reproductive cell. When fungi reproduce asexually, they can spread quickly. This is good when conditions are stable. They can increase their genetic variation by sexual reproduction. This is beneficial when conditions are changing. Variation helps ensure that at least some organisms survive the changing conditions. Figure 9.10 shows how asexual and sexual reproduction occur in fungi. Refer to the figure as you read about each of them below. During asexual reproduction, fungi produce haploid spores by mitosis of a haploid parent cell. A haploid cell has just one of each pair of chromosomes. The haploid spores are genetically identical to the parent cell. Spores may be spread by moving water, wind, or other organisms. Wherever the spores land, they will develop into new hyphae only when conditions are suitable for growth. Yeasts are an exception. They reproduce asexually by budding instead of by producing spores. An offspring cell forms on a parent cell. After it grows and develops, it buds off to form a new cell. The offspring cell is genetically identical to the parent cell. You can see yeast cells budding in Figure 9.11. Sexual reproduction also occurs in most fungi. It happens when two haploid hyphae mate. During mating, two haploid parent cells fuse. The single fused cell that results is a diploid spore. It is genetically different from both parents.
|
When did the earliest fungi evolve?
|
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Fungi (fungus, singular) are relatively simple eukaryotic organisms. They are placed in their own kingdom, the Fungus Kingdom. Most fungi are multicellular organisms. These fungi are called molds. However, some fungi exist as single cells. These fungi are called yeasts. You can see examples of different types of fungi in Figure 9.7. For a funny, fast-paced overview of fungi, watch this video: . MEDIA Click image to the left or use the URL below. URL: For a long time, scientists classified fungi as members of the Plant Kingdom. Fungi share several obvious traits with plants. For example, both fungi and plants lack the ability to move. Both grow in soil, and both have cell walls. Some fungi even look like plants. Today, fungi are no longer classified as plants. We now know that they have important traits that set them apart from plants. Thats why they are placed in their own kingdom. How do fungi differ from plants? The cell walls of fungi are made of chitin. Chitin is a tough carbohydrate that also makes up the outer skeleton of insects. The cell walls of plants are made of cellulose. Fungi are heterotrophs that absorb food from other organisms. Plants are autotrophs that make their own food. The Fungus Kingdom is large and diverse. It may contain more than a million species. However, fewer than 100,000 species of fungi have been identified. The earliest fungi evolved about 600 million years ago. They lived in the water. Fungi colonized the land around the same time as plants. That was probably between 400 and 500 million years ago. After that, fungi became very abundant on land. By 250 million years ago, they may have been the dominant life forms on land. Yeasts grow as single cells. Other fungi grow into multicellular, thread-like structures. These structures are called hyphae (hypha, singular). You can see a photo of hyphae in Figure 9.8. They resemble plant roots. Each hypha consists of a group of cells surrounded by a tubular cell wall. A mass of hyphae make up the body of a fungus. The body is called the mycelium (mycelia, plural). A mycelium may range in size from microscopic to very large. In fact, the largest living thing on Earth is the mycelium of a single fungus. Nicknamed the humongous fungus, it grows in a forest in Oregon. A small part of the fungus is pictured in Figure 9.9. The giant fungus covers an area of 2384 acres. Thats about the size of 1,665 football fields! The fungus is estimated to be at least 2400 years old, but it could be much older. Most fungi reproduce both asexually and sexually. In both types of reproduction, they produce spores. A spore is a special reproductive cell. When fungi reproduce asexually, they can spread quickly. This is good when conditions are stable. They can increase their genetic variation by sexual reproduction. This is beneficial when conditions are changing. Variation helps ensure that at least some organisms survive the changing conditions. Figure 9.10 shows how asexual and sexual reproduction occur in fungi. Refer to the figure as you read about each of them below. During asexual reproduction, fungi produce haploid spores by mitosis of a haploid parent cell. A haploid cell has just one of each pair of chromosomes. The haploid spores are genetically identical to the parent cell. Spores may be spread by moving water, wind, or other organisms. Wherever the spores land, they will develop into new hyphae only when conditions are suitable for growth. Yeasts are an exception. They reproduce asexually by budding instead of by producing spores. An offspring cell forms on a parent cell. After it grows and develops, it buds off to form a new cell. The offspring cell is genetically identical to the parent cell. You can see yeast cells budding in Figure 9.11. Sexual reproduction also occurs in most fungi. It happens when two haploid hyphae mate. During mating, two haploid parent cells fuse. The single fused cell that results is a diploid spore. It is genetically different from both parents.
|
Mycorrhiza is a relationship between a fungus and a
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Fungi (fungus, singular) are relatively simple eukaryotic organisms. They are placed in their own kingdom, the Fungus Kingdom. Most fungi are multicellular organisms. These fungi are called molds. However, some fungi exist as single cells. These fungi are called yeasts. You can see examples of different types of fungi in Figure 9.7. For a funny, fast-paced overview of fungi, watch this video: . MEDIA Click image to the left or use the URL below. URL: For a long time, scientists classified fungi as members of the Plant Kingdom. Fungi share several obvious traits with plants. For example, both fungi and plants lack the ability to move. Both grow in soil, and both have cell walls. Some fungi even look like plants. Today, fungi are no longer classified as plants. We now know that they have important traits that set them apart from plants. Thats why they are placed in their own kingdom. How do fungi differ from plants? The cell walls of fungi are made of chitin. Chitin is a tough carbohydrate that also makes up the outer skeleton of insects. The cell walls of plants are made of cellulose. Fungi are heterotrophs that absorb food from other organisms. Plants are autotrophs that make their own food. The Fungus Kingdom is large and diverse. It may contain more than a million species. However, fewer than 100,000 species of fungi have been identified. The earliest fungi evolved about 600 million years ago. They lived in the water. Fungi colonized the land around the same time as plants. That was probably between 400 and 500 million years ago. After that, fungi became very abundant on land. By 250 million years ago, they may have been the dominant life forms on land. Yeasts grow as single cells. Other fungi grow into multicellular, thread-like structures. These structures are called hyphae (hypha, singular). You can see a photo of hyphae in Figure 9.8. They resemble plant roots. Each hypha consists of a group of cells surrounded by a tubular cell wall. A mass of hyphae make up the body of a fungus. The body is called the mycelium (mycelia, plural). A mycelium may range in size from microscopic to very large. In fact, the largest living thing on Earth is the mycelium of a single fungus. Nicknamed the humongous fungus, it grows in a forest in Oregon. A small part of the fungus is pictured in Figure 9.9. The giant fungus covers an area of 2384 acres. Thats about the size of 1,665 football fields! The fungus is estimated to be at least 2400 years old, but it could be much older. Most fungi reproduce both asexually and sexually. In both types of reproduction, they produce spores. A spore is a special reproductive cell. When fungi reproduce asexually, they can spread quickly. This is good when conditions are stable. They can increase their genetic variation by sexual reproduction. This is beneficial when conditions are changing. Variation helps ensure that at least some organisms survive the changing conditions. Figure 9.10 shows how asexual and sexual reproduction occur in fungi. Refer to the figure as you read about each of them below. During asexual reproduction, fungi produce haploid spores by mitosis of a haploid parent cell. A haploid cell has just one of each pair of chromosomes. The haploid spores are genetically identical to the parent cell. Spores may be spread by moving water, wind, or other organisms. Wherever the spores land, they will develop into new hyphae only when conditions are suitable for growth. Yeasts are an exception. They reproduce asexually by budding instead of by producing spores. An offspring cell forms on a parent cell. After it grows and develops, it buds off to form a new cell. The offspring cell is genetically identical to the parent cell. You can see yeast cells budding in Figure 9.11. Sexual reproduction also occurs in most fungi. It happens when two haploid hyphae mate. During mating, two haploid parent cells fuse. The single fused cell that results is a diploid spore. It is genetically different from both parents.
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___thread-like, multicellular structure produced by a fungus
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Fungi (fungus, singular) are relatively simple eukaryotic organisms. They are placed in their own kingdom, the Fungus Kingdom. Most fungi are multicellular organisms. These fungi are called molds. However, some fungi exist as single cells. These fungi are called yeasts. You can see examples of different types of fungi in Figure 9.7. For a funny, fast-paced overview of fungi, watch this video: . MEDIA Click image to the left or use the URL below. URL: For a long time, scientists classified fungi as members of the Plant Kingdom. Fungi share several obvious traits with plants. For example, both fungi and plants lack the ability to move. Both grow in soil, and both have cell walls. Some fungi even look like plants. Today, fungi are no longer classified as plants. We now know that they have important traits that set them apart from plants. Thats why they are placed in their own kingdom. How do fungi differ from plants? The cell walls of fungi are made of chitin. Chitin is a tough carbohydrate that also makes up the outer skeleton of insects. The cell walls of plants are made of cellulose. Fungi are heterotrophs that absorb food from other organisms. Plants are autotrophs that make their own food. The Fungus Kingdom is large and diverse. It may contain more than a million species. However, fewer than 100,000 species of fungi have been identified. The earliest fungi evolved about 600 million years ago. They lived in the water. Fungi colonized the land around the same time as plants. That was probably between 400 and 500 million years ago. After that, fungi became very abundant on land. By 250 million years ago, they may have been the dominant life forms on land. Yeasts grow as single cells. Other fungi grow into multicellular, thread-like structures. These structures are called hyphae (hypha, singular). You can see a photo of hyphae in Figure 9.8. They resemble plant roots. Each hypha consists of a group of cells surrounded by a tubular cell wall. A mass of hyphae make up the body of a fungus. The body is called the mycelium (mycelia, plural). A mycelium may range in size from microscopic to very large. In fact, the largest living thing on Earth is the mycelium of a single fungus. Nicknamed the humongous fungus, it grows in a forest in Oregon. A small part of the fungus is pictured in Figure 9.9. The giant fungus covers an area of 2384 acres. Thats about the size of 1,665 football fields! The fungus is estimated to be at least 2400 years old, but it could be much older. Most fungi reproduce both asexually and sexually. In both types of reproduction, they produce spores. A spore is a special reproductive cell. When fungi reproduce asexually, they can spread quickly. This is good when conditions are stable. They can increase their genetic variation by sexual reproduction. This is beneficial when conditions are changing. Variation helps ensure that at least some organisms survive the changing conditions. Figure 9.10 shows how asexual and sexual reproduction occur in fungi. Refer to the figure as you read about each of them below. During asexual reproduction, fungi produce haploid spores by mitosis of a haploid parent cell. A haploid cell has just one of each pair of chromosomes. The haploid spores are genetically identical to the parent cell. Spores may be spread by moving water, wind, or other organisms. Wherever the spores land, they will develop into new hyphae only when conditions are suitable for growth. Yeasts are an exception. They reproduce asexually by budding instead of by producing spores. An offspring cell forms on a parent cell. After it grows and develops, it buds off to form a new cell. The offspring cell is genetically identical to the parent cell. You can see yeast cells budding in Figure 9.11. Sexual reproduction also occurs in most fungi. It happens when two haploid hyphae mate. During mating, two haploid parent cells fuse. The single fused cell that results is a diploid spore. It is genetically different from both parents.
|
___method of asexual reproduction in yeasts
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Fungi (fungus, singular) are relatively simple eukaryotic organisms. They are placed in their own kingdom, the Fungus Kingdom. Most fungi are multicellular organisms. These fungi are called molds. However, some fungi exist as single cells. These fungi are called yeasts. You can see examples of different types of fungi in Figure 9.7. For a funny, fast-paced overview of fungi, watch this video: . MEDIA Click image to the left or use the URL below. URL: For a long time, scientists classified fungi as members of the Plant Kingdom. Fungi share several obvious traits with plants. For example, both fungi and plants lack the ability to move. Both grow in soil, and both have cell walls. Some fungi even look like plants. Today, fungi are no longer classified as plants. We now know that they have important traits that set them apart from plants. Thats why they are placed in their own kingdom. How do fungi differ from plants? The cell walls of fungi are made of chitin. Chitin is a tough carbohydrate that also makes up the outer skeleton of insects. The cell walls of plants are made of cellulose. Fungi are heterotrophs that absorb food from other organisms. Plants are autotrophs that make their own food. The Fungus Kingdom is large and diverse. It may contain more than a million species. However, fewer than 100,000 species of fungi have been identified. The earliest fungi evolved about 600 million years ago. They lived in the water. Fungi colonized the land around the same time as plants. That was probably between 400 and 500 million years ago. After that, fungi became very abundant on land. By 250 million years ago, they may have been the dominant life forms on land. Yeasts grow as single cells. Other fungi grow into multicellular, thread-like structures. These structures are called hyphae (hypha, singular). You can see a photo of hyphae in Figure 9.8. They resemble plant roots. Each hypha consists of a group of cells surrounded by a tubular cell wall. A mass of hyphae make up the body of a fungus. The body is called the mycelium (mycelia, plural). A mycelium may range in size from microscopic to very large. In fact, the largest living thing on Earth is the mycelium of a single fungus. Nicknamed the humongous fungus, it grows in a forest in Oregon. A small part of the fungus is pictured in Figure 9.9. The giant fungus covers an area of 2384 acres. Thats about the size of 1,665 football fields! The fungus is estimated to be at least 2400 years old, but it could be much older. Most fungi reproduce both asexually and sexually. In both types of reproduction, they produce spores. A spore is a special reproductive cell. When fungi reproduce asexually, they can spread quickly. This is good when conditions are stable. They can increase their genetic variation by sexual reproduction. This is beneficial when conditions are changing. Variation helps ensure that at least some organisms survive the changing conditions. Figure 9.10 shows how asexual and sexual reproduction occur in fungi. Refer to the figure as you read about each of them below. During asexual reproduction, fungi produce haploid spores by mitosis of a haploid parent cell. A haploid cell has just one of each pair of chromosomes. The haploid spores are genetically identical to the parent cell. Spores may be spread by moving water, wind, or other organisms. Wherever the spores land, they will develop into new hyphae only when conditions are suitable for growth. Yeasts are an exception. They reproduce asexually by budding instead of by producing spores. An offspring cell forms on a parent cell. After it grows and develops, it buds off to form a new cell. The offspring cell is genetically identical to the parent cell. You can see yeast cells budding in Figure 9.11. Sexual reproduction also occurs in most fungi. It happens when two haploid hyphae mate. During mating, two haploid parent cells fuse. The single fused cell that results is a diploid spore. It is genetically different from both parents.
|
___tough carbohydrate that makes up the cell walls of fungi
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Fungi (fungus, singular) are relatively simple eukaryotic organisms. They are placed in their own kingdom, the Fungus Kingdom. Most fungi are multicellular organisms. These fungi are called molds. However, some fungi exist as single cells. These fungi are called yeasts. You can see examples of different types of fungi in Figure 9.7. For a funny, fast-paced overview of fungi, watch this video: . MEDIA Click image to the left or use the URL below. URL: For a long time, scientists classified fungi as members of the Plant Kingdom. Fungi share several obvious traits with plants. For example, both fungi and plants lack the ability to move. Both grow in soil, and both have cell walls. Some fungi even look like plants. Today, fungi are no longer classified as plants. We now know that they have important traits that set them apart from plants. Thats why they are placed in their own kingdom. How do fungi differ from plants? The cell walls of fungi are made of chitin. Chitin is a tough carbohydrate that also makes up the outer skeleton of insects. The cell walls of plants are made of cellulose. Fungi are heterotrophs that absorb food from other organisms. Plants are autotrophs that make their own food. The Fungus Kingdom is large and diverse. It may contain more than a million species. However, fewer than 100,000 species of fungi have been identified. The earliest fungi evolved about 600 million years ago. They lived in the water. Fungi colonized the land around the same time as plants. That was probably between 400 and 500 million years ago. After that, fungi became very abundant on land. By 250 million years ago, they may have been the dominant life forms on land. Yeasts grow as single cells. Other fungi grow into multicellular, thread-like structures. These structures are called hyphae (hypha, singular). You can see a photo of hyphae in Figure 9.8. They resemble plant roots. Each hypha consists of a group of cells surrounded by a tubular cell wall. A mass of hyphae make up the body of a fungus. The body is called the mycelium (mycelia, plural). A mycelium may range in size from microscopic to very large. In fact, the largest living thing on Earth is the mycelium of a single fungus. Nicknamed the humongous fungus, it grows in a forest in Oregon. A small part of the fungus is pictured in Figure 9.9. The giant fungus covers an area of 2384 acres. Thats about the size of 1,665 football fields! The fungus is estimated to be at least 2400 years old, but it could be much older. Most fungi reproduce both asexually and sexually. In both types of reproduction, they produce spores. A spore is a special reproductive cell. When fungi reproduce asexually, they can spread quickly. This is good when conditions are stable. They can increase their genetic variation by sexual reproduction. This is beneficial when conditions are changing. Variation helps ensure that at least some organisms survive the changing conditions. Figure 9.10 shows how asexual and sexual reproduction occur in fungi. Refer to the figure as you read about each of them below. During asexual reproduction, fungi produce haploid spores by mitosis of a haploid parent cell. A haploid cell has just one of each pair of chromosomes. The haploid spores are genetically identical to the parent cell. Spores may be spread by moving water, wind, or other organisms. Wherever the spores land, they will develop into new hyphae only when conditions are suitable for growth. Yeasts are an exception. They reproduce asexually by budding instead of by producing spores. An offspring cell forms on a parent cell. After it grows and develops, it buds off to form a new cell. The offspring cell is genetically identical to the parent cell. You can see yeast cells budding in Figure 9.11. Sexual reproduction also occurs in most fungi. It happens when two haploid hyphae mate. During mating, two haploid parent cells fuse. The single fused cell that results is a diploid spore. It is genetically different from both parents.
|
___body of a multicellular fungus
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Fungi (fungus, singular) are relatively simple eukaryotic organisms. They are placed in their own kingdom, the Fungus Kingdom. Most fungi are multicellular organisms. These fungi are called molds. However, some fungi exist as single cells. These fungi are called yeasts. You can see examples of different types of fungi in Figure 9.7. For a funny, fast-paced overview of fungi, watch this video: . MEDIA Click image to the left or use the URL below. URL: For a long time, scientists classified fungi as members of the Plant Kingdom. Fungi share several obvious traits with plants. For example, both fungi and plants lack the ability to move. Both grow in soil, and both have cell walls. Some fungi even look like plants. Today, fungi are no longer classified as plants. We now know that they have important traits that set them apart from plants. Thats why they are placed in their own kingdom. How do fungi differ from plants? The cell walls of fungi are made of chitin. Chitin is a tough carbohydrate that also makes up the outer skeleton of insects. The cell walls of plants are made of cellulose. Fungi are heterotrophs that absorb food from other organisms. Plants are autotrophs that make their own food. The Fungus Kingdom is large and diverse. It may contain more than a million species. However, fewer than 100,000 species of fungi have been identified. The earliest fungi evolved about 600 million years ago. They lived in the water. Fungi colonized the land around the same time as plants. That was probably between 400 and 500 million years ago. After that, fungi became very abundant on land. By 250 million years ago, they may have been the dominant life forms on land. Yeasts grow as single cells. Other fungi grow into multicellular, thread-like structures. These structures are called hyphae (hypha, singular). You can see a photo of hyphae in Figure 9.8. They resemble plant roots. Each hypha consists of a group of cells surrounded by a tubular cell wall. A mass of hyphae make up the body of a fungus. The body is called the mycelium (mycelia, plural). A mycelium may range in size from microscopic to very large. In fact, the largest living thing on Earth is the mycelium of a single fungus. Nicknamed the humongous fungus, it grows in a forest in Oregon. A small part of the fungus is pictured in Figure 9.9. The giant fungus covers an area of 2384 acres. Thats about the size of 1,665 football fields! The fungus is estimated to be at least 2400 years old, but it could be much older. Most fungi reproduce both asexually and sexually. In both types of reproduction, they produce spores. A spore is a special reproductive cell. When fungi reproduce asexually, they can spread quickly. This is good when conditions are stable. They can increase their genetic variation by sexual reproduction. This is beneficial when conditions are changing. Variation helps ensure that at least some organisms survive the changing conditions. Figure 9.10 shows how asexual and sexual reproduction occur in fungi. Refer to the figure as you read about each of them below. During asexual reproduction, fungi produce haploid spores by mitosis of a haploid parent cell. A haploid cell has just one of each pair of chromosomes. The haploid spores are genetically identical to the parent cell. Spores may be spread by moving water, wind, or other organisms. Wherever the spores land, they will develop into new hyphae only when conditions are suitable for growth. Yeasts are an exception. They reproduce asexually by budding instead of by producing spores. An offspring cell forms on a parent cell. After it grows and develops, it buds off to form a new cell. The offspring cell is genetically identical to the parent cell. You can see yeast cells budding in Figure 9.11. Sexual reproduction also occurs in most fungi. It happens when two haploid hyphae mate. During mating, two haploid parent cells fuse. The single fused cell that results is a diploid spore. It is genetically different from both parents.
|
___reproductive cell produced by a fungus
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Fungi (fungus, singular) are relatively simple eukaryotic organisms. They are placed in their own kingdom, the Fungus Kingdom. Most fungi are multicellular organisms. These fungi are called molds. However, some fungi exist as single cells. These fungi are called yeasts. You can see examples of different types of fungi in Figure 9.7. For a funny, fast-paced overview of fungi, watch this video: . MEDIA Click image to the left or use the URL below. URL: For a long time, scientists classified fungi as members of the Plant Kingdom. Fungi share several obvious traits with plants. For example, both fungi and plants lack the ability to move. Both grow in soil, and both have cell walls. Some fungi even look like plants. Today, fungi are no longer classified as plants. We now know that they have important traits that set them apart from plants. Thats why they are placed in their own kingdom. How do fungi differ from plants? The cell walls of fungi are made of chitin. Chitin is a tough carbohydrate that also makes up the outer skeleton of insects. The cell walls of plants are made of cellulose. Fungi are heterotrophs that absorb food from other organisms. Plants are autotrophs that make their own food. The Fungus Kingdom is large and diverse. It may contain more than a million species. However, fewer than 100,000 species of fungi have been identified. The earliest fungi evolved about 600 million years ago. They lived in the water. Fungi colonized the land around the same time as plants. That was probably between 400 and 500 million years ago. After that, fungi became very abundant on land. By 250 million years ago, they may have been the dominant life forms on land. Yeasts grow as single cells. Other fungi grow into multicellular, thread-like structures. These structures are called hyphae (hypha, singular). You can see a photo of hyphae in Figure 9.8. They resemble plant roots. Each hypha consists of a group of cells surrounded by a tubular cell wall. A mass of hyphae make up the body of a fungus. The body is called the mycelium (mycelia, plural). A mycelium may range in size from microscopic to very large. In fact, the largest living thing on Earth is the mycelium of a single fungus. Nicknamed the humongous fungus, it grows in a forest in Oregon. A small part of the fungus is pictured in Figure 9.9. The giant fungus covers an area of 2384 acres. Thats about the size of 1,665 football fields! The fungus is estimated to be at least 2400 years old, but it could be much older. Most fungi reproduce both asexually and sexually. In both types of reproduction, they produce spores. A spore is a special reproductive cell. When fungi reproduce asexually, they can spread quickly. This is good when conditions are stable. They can increase their genetic variation by sexual reproduction. This is beneficial when conditions are changing. Variation helps ensure that at least some organisms survive the changing conditions. Figure 9.10 shows how asexual and sexual reproduction occur in fungi. Refer to the figure as you read about each of them below. During asexual reproduction, fungi produce haploid spores by mitosis of a haploid parent cell. A haploid cell has just one of each pair of chromosomes. The haploid spores are genetically identical to the parent cell. Spores may be spread by moving water, wind, or other organisms. Wherever the spores land, they will develop into new hyphae only when conditions are suitable for growth. Yeasts are an exception. They reproduce asexually by budding instead of by producing spores. An offspring cell forms on a parent cell. After it grows and develops, it buds off to form a new cell. The offspring cell is genetically identical to the parent cell. You can see yeast cells budding in Figure 9.11. Sexual reproduction also occurs in most fungi. It happens when two haploid hyphae mate. During mating, two haploid parent cells fuse. The single fused cell that results is a diploid spore. It is genetically different from both parents.
|
___type of fungus that exists as single cells
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Einsteins equation is possibly the best-known equation of all time. Theres reason for that. The equation is incredibly important. It changed how scientists view energy and matter, which are two of the most basic concepts in all of science. The equation shows that energy and matter are two forms of the same thing. This new idea turned science upside down when Einstein introduced it in the early 1900s. Amazingly, the idea has withstood the test of time as more and more evidence has been gathered to support it. You can listen to an explanation of Einsteins equation at URL: https://youtu.be/hW7DW9NIO9M Q: What do the letters in Einsteins equation stand for? A: E stands for energy, m stands for mass, and c stands for the speed of light. The speed of light is 300,000 kilometers (186,000 miles) per second, so c2 is a very big number. Therefore, the amount of energy in even a small mass of matter is tremendous. Suppose, for example, that you have 1 gram of matter. Thats about the mass of a paperclip. Multiplying this mass by c2 would yield enough energy to power 3,600 homes for a year! Einsteins equation helps scientists understand what happens in nuclear reactions and why they produce so much energy. When the nucleus of a radioisotope undergoes fission or fusion in a nuclear reaction, it loses a tiny amount of mass. What happens to the lost mass? It isnt really lost at all. It is converted to energy. How much energy? E = mc2 . The change in mass is tiny, but it results in a great deal of energy. Q: In a nuclear reaction, mass decreases and energy increases. What about the laws of conservation of mass and conservation of energy? Are mass and energy not conserved in nuclear reactions? Do we need to throw out these laws when it comes to nuclear reactions? A: No, the laws still apply. However, its more correct to say that the sum of mass and energy is always conserved in a nuclear reaction. Mass changes to energy, but the total amount of mass and energy combined remains the same.
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the letter e in einsteins equation e = mc2 stands for
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"energy."
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You are on vacation at the beach. You take your flip-flops off so you can go swimming. The sand is so hot it hurts your feet. You have to run to the water. Now imagine if it were hot enough for the sand to melt. Some places inside Earth are so hot that rock melts. Melted rock inside the Earth is called magma. Magma can be hotter than 1,000C. When magma erupts onto Earths surface, it is known as lava, as Figure 3.17 shows. Minerals form when magma and lava cool. Most water on Earth, like the water in the oceans, contains elements. The elements are mixed evenly through the water. Water plus other substances makes a solution. The particles are so small that they will not come out when you filter the water. But the elements in water can form solid mineral deposits. Fresh water contains a small amount of dissolved elements. Salt water contains a lot more dissolved elements. Water can only hold a certain amount of dissolved substances. When the water evaporates, it leaves behind a solid layer of minerals, as Figure 3.18 shows. At this time, the particles come together to form minerals. These solids sink to the bottom. The amount of mineral formed is the same as the amount dissolved in the water. Seawater is salty enough for minerals to precipitate as solids. Some lakes, such as Mono Lake in California, or Utahs Great Salt Lake, can also precipitate salts. Salt easily precipitates out of water, as does calcite, as Figure 3.19 shows. The limestone towers in the figure are made mostly of the mineral calcite. The calcite was deposited in the salty and alkaline water of Mono Lake, in California. Calcium-rich spring water enters the bottom of the lake. The water bubbles up into the alkaline lake. The Underground water can be heated by magma. The hot water moves through cracks below Earths surface. Hot water can hold more dissolved particles than cold water. The hot, salty solution has chemical reactions with the rocks around it. The water picks up more dissolved particles. As it flows through open spaces in rocks, the water deposits solid minerals. When a mineral fills cracks in rocks, the deposits are called veins. Figure 3.20 shows a white quartz vein. When the minerals are deposited in open spaces, large crystals grow. These rocks are called geodes. Figure 3.20 shows a geode that was formed when amethyst crystals grew in an open space in a rock.
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Water plus other substances is a(n)
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You are on vacation at the beach. You take your flip-flops off so you can go swimming. The sand is so hot it hurts your feet. You have to run to the water. Now imagine if it were hot enough for the sand to melt. Some places inside Earth are so hot that rock melts. Melted rock inside the Earth is called magma. Magma can be hotter than 1,000C. When magma erupts onto Earths surface, it is known as lava, as Figure 3.17 shows. Minerals form when magma and lava cool. Most water on Earth, like the water in the oceans, contains elements. The elements are mixed evenly through the water. Water plus other substances makes a solution. The particles are so small that they will not come out when you filter the water. But the elements in water can form solid mineral deposits. Fresh water contains a small amount of dissolved elements. Salt water contains a lot more dissolved elements. Water can only hold a certain amount of dissolved substances. When the water evaporates, it leaves behind a solid layer of minerals, as Figure 3.18 shows. At this time, the particles come together to form minerals. These solids sink to the bottom. The amount of mineral formed is the same as the amount dissolved in the water. Seawater is salty enough for minerals to precipitate as solids. Some lakes, such as Mono Lake in California, or Utahs Great Salt Lake, can also precipitate salts. Salt easily precipitates out of water, as does calcite, as Figure 3.19 shows. The limestone towers in the figure are made mostly of the mineral calcite. The calcite was deposited in the salty and alkaline water of Mono Lake, in California. Calcium-rich spring water enters the bottom of the lake. The water bubbles up into the alkaline lake. The Underground water can be heated by magma. The hot water moves through cracks below Earths surface. Hot water can hold more dissolved particles than cold water. The hot, salty solution has chemical reactions with the rocks around it. The water picks up more dissolved particles. As it flows through open spaces in rocks, the water deposits solid minerals. When a mineral fills cracks in rocks, the deposits are called veins. Figure 3.20 shows a white quartz vein. When the minerals are deposited in open spaces, large crystals grow. These rocks are called geodes. Figure 3.20 shows a geode that was formed when amethyst crystals grew in an open space in a rock.
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Dissolved elements in water can form
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You are on vacation at the beach. You take your flip-flops off so you can go swimming. The sand is so hot it hurts your feet. You have to run to the water. Now imagine if it were hot enough for the sand to melt. Some places inside Earth are so hot that rock melts. Melted rock inside the Earth is called magma. Magma can be hotter than 1,000C. When magma erupts onto Earths surface, it is known as lava, as Figure 3.17 shows. Minerals form when magma and lava cool. Most water on Earth, like the water in the oceans, contains elements. The elements are mixed evenly through the water. Water plus other substances makes a solution. The particles are so small that they will not come out when you filter the water. But the elements in water can form solid mineral deposits. Fresh water contains a small amount of dissolved elements. Salt water contains a lot more dissolved elements. Water can only hold a certain amount of dissolved substances. When the water evaporates, it leaves behind a solid layer of minerals, as Figure 3.18 shows. At this time, the particles come together to form minerals. These solids sink to the bottom. The amount of mineral formed is the same as the amount dissolved in the water. Seawater is salty enough for minerals to precipitate as solids. Some lakes, such as Mono Lake in California, or Utahs Great Salt Lake, can also precipitate salts. Salt easily precipitates out of water, as does calcite, as Figure 3.19 shows. The limestone towers in the figure are made mostly of the mineral calcite. The calcite was deposited in the salty and alkaline water of Mono Lake, in California. Calcium-rich spring water enters the bottom of the lake. The water bubbles up into the alkaline lake. The Underground water can be heated by magma. The hot water moves through cracks below Earths surface. Hot water can hold more dissolved particles than cold water. The hot, salty solution has chemical reactions with the rocks around it. The water picks up more dissolved particles. As it flows through open spaces in rocks, the water deposits solid minerals. When a mineral fills cracks in rocks, the deposits are called veins. Figure 3.20 shows a white quartz vein. When the minerals are deposited in open spaces, large crystals grow. These rocks are called geodes. Figure 3.20 shows a geode that was formed when amethyst crystals grew in an open space in a rock.
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Underground water is heated by
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You are on vacation at the beach. You take your flip-flops off so you can go swimming. The sand is so hot it hurts your feet. You have to run to the water. Now imagine if it were hot enough for the sand to melt. Some places inside Earth are so hot that rock melts. Melted rock inside the Earth is called magma. Magma can be hotter than 1,000C. When magma erupts onto Earths surface, it is known as lava, as Figure 3.17 shows. Minerals form when magma and lava cool. Most water on Earth, like the water in the oceans, contains elements. The elements are mixed evenly through the water. Water plus other substances makes a solution. The particles are so small that they will not come out when you filter the water. But the elements in water can form solid mineral deposits. Fresh water contains a small amount of dissolved elements. Salt water contains a lot more dissolved elements. Water can only hold a certain amount of dissolved substances. When the water evaporates, it leaves behind a solid layer of minerals, as Figure 3.18 shows. At this time, the particles come together to form minerals. These solids sink to the bottom. The amount of mineral formed is the same as the amount dissolved in the water. Seawater is salty enough for minerals to precipitate as solids. Some lakes, such as Mono Lake in California, or Utahs Great Salt Lake, can also precipitate salts. Salt easily precipitates out of water, as does calcite, as Figure 3.19 shows. The limestone towers in the figure are made mostly of the mineral calcite. The calcite was deposited in the salty and alkaline water of Mono Lake, in California. Calcium-rich spring water enters the bottom of the lake. The water bubbles up into the alkaline lake. The Underground water can be heated by magma. The hot water moves through cracks below Earths surface. Hot water can hold more dissolved particles than cold water. The hot, salty solution has chemical reactions with the rocks around it. The water picks up more dissolved particles. As it flows through open spaces in rocks, the water deposits solid minerals. When a mineral fills cracks in rocks, the deposits are called veins. Figure 3.20 shows a white quartz vein. When the minerals are deposited in open spaces, large crystals grow. These rocks are called geodes. Figure 3.20 shows a geode that was formed when amethyst crystals grew in an open space in a rock.
|
As the water in a solution evaporates,
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You are on vacation at the beach. You take your flip-flops off so you can go swimming. The sand is so hot it hurts your feet. You have to run to the water. Now imagine if it were hot enough for the sand to melt. Some places inside Earth are so hot that rock melts. Melted rock inside the Earth is called magma. Magma can be hotter than 1,000C. When magma erupts onto Earths surface, it is known as lava, as Figure 3.17 shows. Minerals form when magma and lava cool. Most water on Earth, like the water in the oceans, contains elements. The elements are mixed evenly through the water. Water plus other substances makes a solution. The particles are so small that they will not come out when you filter the water. But the elements in water can form solid mineral deposits. Fresh water contains a small amount of dissolved elements. Salt water contains a lot more dissolved elements. Water can only hold a certain amount of dissolved substances. When the water evaporates, it leaves behind a solid layer of minerals, as Figure 3.18 shows. At this time, the particles come together to form minerals. These solids sink to the bottom. The amount of mineral formed is the same as the amount dissolved in the water. Seawater is salty enough for minerals to precipitate as solids. Some lakes, such as Mono Lake in California, or Utahs Great Salt Lake, can also precipitate salts. Salt easily precipitates out of water, as does calcite, as Figure 3.19 shows. The limestone towers in the figure are made mostly of the mineral calcite. The calcite was deposited in the salty and alkaline water of Mono Lake, in California. Calcium-rich spring water enters the bottom of the lake. The water bubbles up into the alkaline lake. The Underground water can be heated by magma. The hot water moves through cracks below Earths surface. Hot water can hold more dissolved particles than cold water. The hot, salty solution has chemical reactions with the rocks around it. The water picks up more dissolved particles. As it flows through open spaces in rocks, the water deposits solid minerals. When a mineral fills cracks in rocks, the deposits are called veins. Figure 3.20 shows a white quartz vein. When the minerals are deposited in open spaces, large crystals grow. These rocks are called geodes. Figure 3.20 shows a geode that was formed when amethyst crystals grew in an open space in a rock.
|
Which type of feature may form in open spaces inside rocks?
|
[
"geode"
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You are on vacation at the beach. You take your flip-flops off so you can go swimming. The sand is so hot it hurts your feet. You have to run to the water. Now imagine if it were hot enough for the sand to melt. Some places inside Earth are so hot that rock melts. Melted rock inside the Earth is called magma. Magma can be hotter than 1,000C. When magma erupts onto Earths surface, it is known as lava, as Figure 3.17 shows. Minerals form when magma and lava cool. Most water on Earth, like the water in the oceans, contains elements. The elements are mixed evenly through the water. Water plus other substances makes a solution. The particles are so small that they will not come out when you filter the water. But the elements in water can form solid mineral deposits. Fresh water contains a small amount of dissolved elements. Salt water contains a lot more dissolved elements. Water can only hold a certain amount of dissolved substances. When the water evaporates, it leaves behind a solid layer of minerals, as Figure 3.18 shows. At this time, the particles come together to form minerals. These solids sink to the bottom. The amount of mineral formed is the same as the amount dissolved in the water. Seawater is salty enough for minerals to precipitate as solids. Some lakes, such as Mono Lake in California, or Utahs Great Salt Lake, can also precipitate salts. Salt easily precipitates out of water, as does calcite, as Figure 3.19 shows. The limestone towers in the figure are made mostly of the mineral calcite. The calcite was deposited in the salty and alkaline water of Mono Lake, in California. Calcium-rich spring water enters the bottom of the lake. The water bubbles up into the alkaline lake. The Underground water can be heated by magma. The hot water moves through cracks below Earths surface. Hot water can hold more dissolved particles than cold water. The hot, salty solution has chemical reactions with the rocks around it. The water picks up more dissolved particles. As it flows through open spaces in rocks, the water deposits solid minerals. When a mineral fills cracks in rocks, the deposits are called veins. Figure 3.20 shows a white quartz vein. When the minerals are deposited in open spaces, large crystals grow. These rocks are called geodes. Figure 3.20 shows a geode that was formed when amethyst crystals grew in an open space in a rock.
|
Melted rock that erupts on to Earths surface is called
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[
"lava"
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You are on vacation at the beach. You take your flip-flops off so you can go swimming. The sand is so hot it hurts your feet. You have to run to the water. Now imagine if it were hot enough for the sand to melt. Some places inside Earth are so hot that rock melts. Melted rock inside the Earth is called magma. Magma can be hotter than 1,000C. When magma erupts onto Earths surface, it is known as lava, as Figure 3.17 shows. Minerals form when magma and lava cool. Most water on Earth, like the water in the oceans, contains elements. The elements are mixed evenly through the water. Water plus other substances makes a solution. The particles are so small that they will not come out when you filter the water. But the elements in water can form solid mineral deposits. Fresh water contains a small amount of dissolved elements. Salt water contains a lot more dissolved elements. Water can only hold a certain amount of dissolved substances. When the water evaporates, it leaves behind a solid layer of minerals, as Figure 3.18 shows. At this time, the particles come together to form minerals. These solids sink to the bottom. The amount of mineral formed is the same as the amount dissolved in the water. Seawater is salty enough for minerals to precipitate as solids. Some lakes, such as Mono Lake in California, or Utahs Great Salt Lake, can also precipitate salts. Salt easily precipitates out of water, as does calcite, as Figure 3.19 shows. The limestone towers in the figure are made mostly of the mineral calcite. The calcite was deposited in the salty and alkaline water of Mono Lake, in California. Calcium-rich spring water enters the bottom of the lake. The water bubbles up into the alkaline lake. The Underground water can be heated by magma. The hot water moves through cracks below Earths surface. Hot water can hold more dissolved particles than cold water. The hot, salty solution has chemical reactions with the rocks around it. The water picks up more dissolved particles. As it flows through open spaces in rocks, the water deposits solid minerals. When a mineral fills cracks in rocks, the deposits are called veins. Figure 3.20 shows a white quartz vein. When the minerals are deposited in open spaces, large crystals grow. These rocks are called geodes. Figure 3.20 shows a geode that was formed when amethyst crystals grew in an open space in a rock.
|
Water in rocks underground can be heated by
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You are on vacation at the beach. You take your flip-flops off so you can go swimming. The sand is so hot it hurts your feet. You have to run to the water. Now imagine if it were hot enough for the sand to melt. Some places inside Earth are so hot that rock melts. Melted rock inside the Earth is called magma. Magma can be hotter than 1,000C. When magma erupts onto Earths surface, it is known as lava, as Figure 3.17 shows. Minerals form when magma and lava cool. Most water on Earth, like the water in the oceans, contains elements. The elements are mixed evenly through the water. Water plus other substances makes a solution. The particles are so small that they will not come out when you filter the water. But the elements in water can form solid mineral deposits. Fresh water contains a small amount of dissolved elements. Salt water contains a lot more dissolved elements. Water can only hold a certain amount of dissolved substances. When the water evaporates, it leaves behind a solid layer of minerals, as Figure 3.18 shows. At this time, the particles come together to form minerals. These solids sink to the bottom. The amount of mineral formed is the same as the amount dissolved in the water. Seawater is salty enough for minerals to precipitate as solids. Some lakes, such as Mono Lake in California, or Utahs Great Salt Lake, can also precipitate salts. Salt easily precipitates out of water, as does calcite, as Figure 3.19 shows. The limestone towers in the figure are made mostly of the mineral calcite. The calcite was deposited in the salty and alkaline water of Mono Lake, in California. Calcium-rich spring water enters the bottom of the lake. The water bubbles up into the alkaline lake. The Underground water can be heated by magma. The hot water moves through cracks below Earths surface. Hot water can hold more dissolved particles than cold water. The hot, salty solution has chemical reactions with the rocks around it. The water picks up more dissolved particles. As it flows through open spaces in rocks, the water deposits solid minerals. When a mineral fills cracks in rocks, the deposits are called veins. Figure 3.20 shows a white quartz vein. When the minerals are deposited in open spaces, large crystals grow. These rocks are called geodes. Figure 3.20 shows a geode that was formed when amethyst crystals grew in an open space in a rock.
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to come out of a solution as a solid
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You are on vacation at the beach. You take your flip-flops off so you can go swimming. The sand is so hot it hurts your feet. You have to run to the water. Now imagine if it were hot enough for the sand to melt. Some places inside Earth are so hot that rock melts. Melted rock inside the Earth is called magma. Magma can be hotter than 1,000C. When magma erupts onto Earths surface, it is known as lava, as Figure 3.17 shows. Minerals form when magma and lava cool. Most water on Earth, like the water in the oceans, contains elements. The elements are mixed evenly through the water. Water plus other substances makes a solution. The particles are so small that they will not come out when you filter the water. But the elements in water can form solid mineral deposits. Fresh water contains a small amount of dissolved elements. Salt water contains a lot more dissolved elements. Water can only hold a certain amount of dissolved substances. When the water evaporates, it leaves behind a solid layer of minerals, as Figure 3.18 shows. At this time, the particles come together to form minerals. These solids sink to the bottom. The amount of mineral formed is the same as the amount dissolved in the water. Seawater is salty enough for minerals to precipitate as solids. Some lakes, such as Mono Lake in California, or Utahs Great Salt Lake, can also precipitate salts. Salt easily precipitates out of water, as does calcite, as Figure 3.19 shows. The limestone towers in the figure are made mostly of the mineral calcite. The calcite was deposited in the salty and alkaline water of Mono Lake, in California. Calcium-rich spring water enters the bottom of the lake. The water bubbles up into the alkaline lake. The Underground water can be heated by magma. The hot water moves through cracks below Earths surface. Hot water can hold more dissolved particles than cold water. The hot, salty solution has chemical reactions with the rocks around it. The water picks up more dissolved particles. As it flows through open spaces in rocks, the water deposits solid minerals. When a mineral fills cracks in rocks, the deposits are called veins. Figure 3.20 shows a white quartz vein. When the minerals are deposited in open spaces, large crystals grow. These rocks are called geodes. Figure 3.20 shows a geode that was formed when amethyst crystals grew in an open space in a rock.
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water mixed with dissolved substances
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You are on vacation at the beach. You take your flip-flops off so you can go swimming. The sand is so hot it hurts your feet. You have to run to the water. Now imagine if it were hot enough for the sand to melt. Some places inside Earth are so hot that rock melts. Melted rock inside the Earth is called magma. Magma can be hotter than 1,000C. When magma erupts onto Earths surface, it is known as lava, as Figure 3.17 shows. Minerals form when magma and lava cool. Most water on Earth, like the water in the oceans, contains elements. The elements are mixed evenly through the water. Water plus other substances makes a solution. The particles are so small that they will not come out when you filter the water. But the elements in water can form solid mineral deposits. Fresh water contains a small amount of dissolved elements. Salt water contains a lot more dissolved elements. Water can only hold a certain amount of dissolved substances. When the water evaporates, it leaves behind a solid layer of minerals, as Figure 3.18 shows. At this time, the particles come together to form minerals. These solids sink to the bottom. The amount of mineral formed is the same as the amount dissolved in the water. Seawater is salty enough for minerals to precipitate as solids. Some lakes, such as Mono Lake in California, or Utahs Great Salt Lake, can also precipitate salts. Salt easily precipitates out of water, as does calcite, as Figure 3.19 shows. The limestone towers in the figure are made mostly of the mineral calcite. The calcite was deposited in the salty and alkaline water of Mono Lake, in California. Calcium-rich spring water enters the bottom of the lake. The water bubbles up into the alkaline lake. The Underground water can be heated by magma. The hot water moves through cracks below Earths surface. Hot water can hold more dissolved particles than cold water. The hot, salty solution has chemical reactions with the rocks around it. The water picks up more dissolved particles. As it flows through open spaces in rocks, the water deposits solid minerals. When a mineral fills cracks in rocks, the deposits are called veins. Figure 3.20 shows a white quartz vein. When the minerals are deposited in open spaces, large crystals grow. These rocks are called geodes. Figure 3.20 shows a geode that was formed when amethyst crystals grew in an open space in a rock.
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solid mixture of minerals
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You are on vacation at the beach. You take your flip-flops off so you can go swimming. The sand is so hot it hurts your feet. You have to run to the water. Now imagine if it were hot enough for the sand to melt. Some places inside Earth are so hot that rock melts. Melted rock inside the Earth is called magma. Magma can be hotter than 1,000C. When magma erupts onto Earths surface, it is known as lava, as Figure 3.17 shows. Minerals form when magma and lava cool. Most water on Earth, like the water in the oceans, contains elements. The elements are mixed evenly through the water. Water plus other substances makes a solution. The particles are so small that they will not come out when you filter the water. But the elements in water can form solid mineral deposits. Fresh water contains a small amount of dissolved elements. Salt water contains a lot more dissolved elements. Water can only hold a certain amount of dissolved substances. When the water evaporates, it leaves behind a solid layer of minerals, as Figure 3.18 shows. At this time, the particles come together to form minerals. These solids sink to the bottom. The amount of mineral formed is the same as the amount dissolved in the water. Seawater is salty enough for minerals to precipitate as solids. Some lakes, such as Mono Lake in California, or Utahs Great Salt Lake, can also precipitate salts. Salt easily precipitates out of water, as does calcite, as Figure 3.19 shows. The limestone towers in the figure are made mostly of the mineral calcite. The calcite was deposited in the salty and alkaline water of Mono Lake, in California. Calcium-rich spring water enters the bottom of the lake. The water bubbles up into the alkaline lake. The Underground water can be heated by magma. The hot water moves through cracks below Earths surface. Hot water can hold more dissolved particles than cold water. The hot, salty solution has chemical reactions with the rocks around it. The water picks up more dissolved particles. As it flows through open spaces in rocks, the water deposits solid minerals. When a mineral fills cracks in rocks, the deposits are called veins. Figure 3.20 shows a white quartz vein. When the minerals are deposited in open spaces, large crystals grow. These rocks are called geodes. Figure 3.20 shows a geode that was formed when amethyst crystals grew in an open space in a rock.
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melted rock below Earths surface
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You are on vacation at the beach. You take your flip-flops off so you can go swimming. The sand is so hot it hurts your feet. You have to run to the water. Now imagine if it were hot enough for the sand to melt. Some places inside Earth are so hot that rock melts. Melted rock inside the Earth is called magma. Magma can be hotter than 1,000C. When magma erupts onto Earths surface, it is known as lava, as Figure 3.17 shows. Minerals form when magma and lava cool. Most water on Earth, like the water in the oceans, contains elements. The elements are mixed evenly through the water. Water plus other substances makes a solution. The particles are so small that they will not come out when you filter the water. But the elements in water can form solid mineral deposits. Fresh water contains a small amount of dissolved elements. Salt water contains a lot more dissolved elements. Water can only hold a certain amount of dissolved substances. When the water evaporates, it leaves behind a solid layer of minerals, as Figure 3.18 shows. At this time, the particles come together to form minerals. These solids sink to the bottom. The amount of mineral formed is the same as the amount dissolved in the water. Seawater is salty enough for minerals to precipitate as solids. Some lakes, such as Mono Lake in California, or Utahs Great Salt Lake, can also precipitate salts. Salt easily precipitates out of water, as does calcite, as Figure 3.19 shows. The limestone towers in the figure are made mostly of the mineral calcite. The calcite was deposited in the salty and alkaline water of Mono Lake, in California. Calcium-rich spring water enters the bottom of the lake. The water bubbles up into the alkaline lake. The Underground water can be heated by magma. The hot water moves through cracks below Earths surface. Hot water can hold more dissolved particles than cold water. The hot, salty solution has chemical reactions with the rocks around it. The water picks up more dissolved particles. As it flows through open spaces in rocks, the water deposits solid minerals. When a mineral fills cracks in rocks, the deposits are called veins. Figure 3.20 shows a white quartz vein. When the minerals are deposited in open spaces, large crystals grow. These rocks are called geodes. Figure 3.20 shows a geode that was formed when amethyst crystals grew in an open space in a rock.
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melted rock that has erupted onto Earths surface
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You are on vacation at the beach. You take your flip-flops off so you can go swimming. The sand is so hot it hurts your feet. You have to run to the water. Now imagine if it were hot enough for the sand to melt. Some places inside Earth are so hot that rock melts. Melted rock inside the Earth is called magma. Magma can be hotter than 1,000C. When magma erupts onto Earths surface, it is known as lava, as Figure 3.17 shows. Minerals form when magma and lava cool. Most water on Earth, like the water in the oceans, contains elements. The elements are mixed evenly through the water. Water plus other substances makes a solution. The particles are so small that they will not come out when you filter the water. But the elements in water can form solid mineral deposits. Fresh water contains a small amount of dissolved elements. Salt water contains a lot more dissolved elements. Water can only hold a certain amount of dissolved substances. When the water evaporates, it leaves behind a solid layer of minerals, as Figure 3.18 shows. At this time, the particles come together to form minerals. These solids sink to the bottom. The amount of mineral formed is the same as the amount dissolved in the water. Seawater is salty enough for minerals to precipitate as solids. Some lakes, such as Mono Lake in California, or Utahs Great Salt Lake, can also precipitate salts. Salt easily precipitates out of water, as does calcite, as Figure 3.19 shows. The limestone towers in the figure are made mostly of the mineral calcite. The calcite was deposited in the salty and alkaline water of Mono Lake, in California. Calcium-rich spring water enters the bottom of the lake. The water bubbles up into the alkaline lake. The Underground water can be heated by magma. The hot water moves through cracks below Earths surface. Hot water can hold more dissolved particles than cold water. The hot, salty solution has chemical reactions with the rocks around it. The water picks up more dissolved particles. As it flows through open spaces in rocks, the water deposits solid minerals. When a mineral fills cracks in rocks, the deposits are called veins. Figure 3.20 shows a white quartz vein. When the minerals are deposited in open spaces, large crystals grow. These rocks are called geodes. Figure 3.20 shows a geode that was formed when amethyst crystals grew in an open space in a rock.
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long, narrow mineral deposit
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You are on vacation at the beach. You take your flip-flops off so you can go swimming. The sand is so hot it hurts your feet. You have to run to the water. Now imagine if it were hot enough for the sand to melt. Some places inside Earth are so hot that rock melts. Melted rock inside the Earth is called magma. Magma can be hotter than 1,000C. When magma erupts onto Earths surface, it is known as lava, as Figure 3.17 shows. Minerals form when magma and lava cool. Most water on Earth, like the water in the oceans, contains elements. The elements are mixed evenly through the water. Water plus other substances makes a solution. The particles are so small that they will not come out when you filter the water. But the elements in water can form solid mineral deposits. Fresh water contains a small amount of dissolved elements. Salt water contains a lot more dissolved elements. Water can only hold a certain amount of dissolved substances. When the water evaporates, it leaves behind a solid layer of minerals, as Figure 3.18 shows. At this time, the particles come together to form minerals. These solids sink to the bottom. The amount of mineral formed is the same as the amount dissolved in the water. Seawater is salty enough for minerals to precipitate as solids. Some lakes, such as Mono Lake in California, or Utahs Great Salt Lake, can also precipitate salts. Salt easily precipitates out of water, as does calcite, as Figure 3.19 shows. The limestone towers in the figure are made mostly of the mineral calcite. The calcite was deposited in the salty and alkaline water of Mono Lake, in California. Calcium-rich spring water enters the bottom of the lake. The water bubbles up into the alkaline lake. The Underground water can be heated by magma. The hot water moves through cracks below Earths surface. Hot water can hold more dissolved particles than cold water. The hot, salty solution has chemical reactions with the rocks around it. The water picks up more dissolved particles. As it flows through open spaces in rocks, the water deposits solid minerals. When a mineral fills cracks in rocks, the deposits are called veins. Figure 3.20 shows a white quartz vein. When the minerals are deposited in open spaces, large crystals grow. These rocks are called geodes. Figure 3.20 shows a geode that was formed when amethyst crystals grew in an open space in a rock.
|
rock formed by the growth of large mineral crystals
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Ions come together to create a molecule so that electrical charges are balanced; the positive charges balance the negative charges and the molecule has no electrical charge. To balance electrical charge, an atom may share its electron with another atom, give it away, or receive an electron from another atom. The joining of ions to make molecules is called chemical bonding. There are three main types of chemical bonds that are important in our discussion of minerals and rocks: Ionic bond: Electrons are transferred between atoms. An ion will give one or more electrons to another ion. Table salt, sodium chloride (NaCl), is a common example of an ionic compound. Note that sodium is on the left side of the periodic table and that chlorine is on the right side of the periodic table. In the Figure 1.2, an atom of lithium donates an electron to an atom of fluorine to form an ionic compound. The transfer of the electron gives the lithium ion a net charge of +1, and the fluorine ion a net charge of -1. These ions bond because they experience an attractive force due to the difference in sign of their charges. Covalent bond : In a covalent bond, an atom shares one or more electrons with another atom. Periodic Table of the Elements. Lithium (left) and fluorine (right) form an ionic compound called lithium fluoride. In the picture of methane (CH4 ) below (Figure 1.3), the carbon ion (with a net charge of +4) shares a single electron from each of the the four hydrogens. Covalent bonding is prevalent in organic compounds. In fact, your body is held together by electrons shared by carbons and hydrogens! Covalent bonds are also very strong, meaning it takes a lot of energy to break them apart. Hydrogen bond: These weak, intermolecular bonds are formed when the positive side of one polar molecule is attracted to the negative side of another polar molecule. Water is a classic example of a polar molecule because it has a slightly positive side, and a slightly negative side. In fact, this property is why water is so good at dissolving things. The positive side of the molecule is attracted to Methane is formed when four hydrogens and one carbon covalently bond. negative ions and the negative side is attracted to positive ions.
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an atom that shares one or more electrons with another atom is a(n)
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The history of the atom begins around 450 B.C. with a Greek philosopher named Democritus (see Figure 5.7). Democritus wondered what would happen if you cut a piece of matter, such as an apple, into smaller and smaller pieces. He thought that a point would be reached where matter could not be cut into still smaller pieces. He called these "uncuttable" pieces atomos. This is where the modern term atom comes from. Democritus was an important philosopher. However, he was less influential than the Greek philosopher Aristotle, who lived about 100 years after Democritus. Aristotle rejected Democrituss idea of atoms. In fact, Aristotle thought Around 1800, a British chemist named John Dalton revived Democrituss early ideas about the atom. Dalton is pictured in Figure 5.8. He made a living by teaching and just did research in his spare time. Nonetheless, from his research results, he developed one of the most important theories in science. Dalton did many experiments that provided evidence for atoms. For example, he studied the pressure of gases. He concluded that gases must consist of tiny particles in constant motion. Dalton also researched the properties of compounds. He showed that a compound always consists of the same elements in the same ratio. On the other hand, different compounds always consist of different elements or ratios. This can happen, Dalton reasoned, only if elements are made of tiny particles that can combine in an endless variety of ways. From his research, Dalton developed a theory of the atom. You can learn more about Dalton and his research by watching the video at this URL: (9:03). MEDIA Click image to the left or use the URL below. URL: The atomic theory Dalton developed consists of three ideas: All substances are made of atoms. Atoms are the smallest particles of matter. They cannot be divided into smaller particles. They also cannot be created or destroyed. All atoms of the same element are alike and have the same mass. Atoms of different elements are different and have different masses. Atoms join together to form compounds. A given compound always consists of the same kinds of atoms in the same ratio. Daltons theory was soon widely accepted. Most of it is still accepted today. The only part that is no longer accepted is his idea that atoms are the smallest particles. Scientists now know that atoms consist of even smaller particles. Dalton incorrectly thought that atoms are tiny solid particles of matter. He used solid wooden balls to model them. The sketch in the Figure 5.9 shows how Daltons model atoms looked. He made holes in the balls so they could be joined together with hooks. In this way, the balls could be used to model compounds. When later scientists discovered subatomic particles (particles smaller than the atom itself), they realized that Daltons models were too simple. They didnt show that atoms consist of even smaller particles. Models including these smaller particles were later developed. The next major advance in the history of the atom was the discovery of electrons. These were the first subatomic particles to be identified. They were discovered in 1897 by a British physicist named J. J. Thomson. You can learn more about Thomson and his discovery at this online exhibit: . Thomson was interested in electricity. He did experiments in which he passed an electric current through a vacuum tube. The experiments are described in Figure 5.10. Thomsons experiments showed that an electric current consists of flowing, negatively charged particles. Why was this discovery important? Many scientists of Thomsons time thought that electric current consists of rays, like rays of light, and that it is positive rather than negative. Thomsons experiments also showed that the negative particles are all alike and smaller than atoms. Thomson concluded that the negative particles couldnt be fundamental units of matter because they are all alike. Instead, they must be parts of atoms. The negative particles were later named electrons. Thomson knew that atoms are neutral in electric charge. So how could atoms contain negative particles? Thomson thought that the rest of the atom must be positive to cancel out the negative charge. He said that an atom is like
|
scientist who discovered electrons.
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The history of the atom begins around 450 B.C. with a Greek philosopher named Democritus (see Figure 5.7). Democritus wondered what would happen if you cut a piece of matter, such as an apple, into smaller and smaller pieces. He thought that a point would be reached where matter could not be cut into still smaller pieces. He called these "uncuttable" pieces atomos. This is where the modern term atom comes from. Democritus was an important philosopher. However, he was less influential than the Greek philosopher Aristotle, who lived about 100 years after Democritus. Aristotle rejected Democrituss idea of atoms. In fact, Aristotle thought Around 1800, a British chemist named John Dalton revived Democrituss early ideas about the atom. Dalton is pictured in Figure 5.8. He made a living by teaching and just did research in his spare time. Nonetheless, from his research results, he developed one of the most important theories in science. Dalton did many experiments that provided evidence for atoms. For example, he studied the pressure of gases. He concluded that gases must consist of tiny particles in constant motion. Dalton also researched the properties of compounds. He showed that a compound always consists of the same elements in the same ratio. On the other hand, different compounds always consist of different elements or ratios. This can happen, Dalton reasoned, only if elements are made of tiny particles that can combine in an endless variety of ways. From his research, Dalton developed a theory of the atom. You can learn more about Dalton and his research by watching the video at this URL: (9:03). MEDIA Click image to the left or use the URL below. URL: The atomic theory Dalton developed consists of three ideas: All substances are made of atoms. Atoms are the smallest particles of matter. They cannot be divided into smaller particles. They also cannot be created or destroyed. All atoms of the same element are alike and have the same mass. Atoms of different elements are different and have different masses. Atoms join together to form compounds. A given compound always consists of the same kinds of atoms in the same ratio. Daltons theory was soon widely accepted. Most of it is still accepted today. The only part that is no longer accepted is his idea that atoms are the smallest particles. Scientists now know that atoms consist of even smaller particles. Dalton incorrectly thought that atoms are tiny solid particles of matter. He used solid wooden balls to model them. The sketch in the Figure 5.9 shows how Daltons model atoms looked. He made holes in the balls so they could be joined together with hooks. In this way, the balls could be used to model compounds. When later scientists discovered subatomic particles (particles smaller than the atom itself), they realized that Daltons models were too simple. They didnt show that atoms consist of even smaller particles. Models including these smaller particles were later developed. The next major advance in the history of the atom was the discovery of electrons. These were the first subatomic particles to be identified. They were discovered in 1897 by a British physicist named J. J. Thomson. You can learn more about Thomson and his discovery at this online exhibit: . Thomson was interested in electricity. He did experiments in which he passed an electric current through a vacuum tube. The experiments are described in Figure 5.10. Thomsons experiments showed that an electric current consists of flowing, negatively charged particles. Why was this discovery important? Many scientists of Thomsons time thought that electric current consists of rays, like rays of light, and that it is positive rather than negative. Thomsons experiments also showed that the negative particles are all alike and smaller than atoms. Thomson concluded that the negative particles couldnt be fundamental units of matter because they are all alike. Instead, they must be parts of atoms. The negative particles were later named electrons. Thomson knew that atoms are neutral in electric charge. So how could atoms contain negative particles? Thomson thought that the rest of the atom must be positive to cancel out the negative charge. He said that an atom is like
|
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|
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The history of the atom begins around 450 B.C. with a Greek philosopher named Democritus (see Figure 5.7). Democritus wondered what would happen if you cut a piece of matter, such as an apple, into smaller and smaller pieces. He thought that a point would be reached where matter could not be cut into still smaller pieces. He called these "uncuttable" pieces atomos. This is where the modern term atom comes from. Democritus was an important philosopher. However, he was less influential than the Greek philosopher Aristotle, who lived about 100 years after Democritus. Aristotle rejected Democrituss idea of atoms. In fact, Aristotle thought Around 1800, a British chemist named John Dalton revived Democrituss early ideas about the atom. Dalton is pictured in Figure 5.8. He made a living by teaching and just did research in his spare time. Nonetheless, from his research results, he developed one of the most important theories in science. Dalton did many experiments that provided evidence for atoms. For example, he studied the pressure of gases. He concluded that gases must consist of tiny particles in constant motion. Dalton also researched the properties of compounds. He showed that a compound always consists of the same elements in the same ratio. On the other hand, different compounds always consist of different elements or ratios. This can happen, Dalton reasoned, only if elements are made of tiny particles that can combine in an endless variety of ways. From his research, Dalton developed a theory of the atom. You can learn more about Dalton and his research by watching the video at this URL: (9:03). MEDIA Click image to the left or use the URL below. URL: The atomic theory Dalton developed consists of three ideas: All substances are made of atoms. Atoms are the smallest particles of matter. They cannot be divided into smaller particles. They also cannot be created or destroyed. All atoms of the same element are alike and have the same mass. Atoms of different elements are different and have different masses. Atoms join together to form compounds. A given compound always consists of the same kinds of atoms in the same ratio. Daltons theory was soon widely accepted. Most of it is still accepted today. The only part that is no longer accepted is his idea that atoms are the smallest particles. Scientists now know that atoms consist of even smaller particles. Dalton incorrectly thought that atoms are tiny solid particles of matter. He used solid wooden balls to model them. The sketch in the Figure 5.9 shows how Daltons model atoms looked. He made holes in the balls so they could be joined together with hooks. In this way, the balls could be used to model compounds. When later scientists discovered subatomic particles (particles smaller than the atom itself), they realized that Daltons models were too simple. They didnt show that atoms consist of even smaller particles. Models including these smaller particles were later developed. The next major advance in the history of the atom was the discovery of electrons. These were the first subatomic particles to be identified. They were discovered in 1897 by a British physicist named J. J. Thomson. You can learn more about Thomson and his discovery at this online exhibit: . Thomson was interested in electricity. He did experiments in which he passed an electric current through a vacuum tube. The experiments are described in Figure 5.10. Thomsons experiments showed that an electric current consists of flowing, negatively charged particles. Why was this discovery important? Many scientists of Thomsons time thought that electric current consists of rays, like rays of light, and that it is positive rather than negative. Thomsons experiments also showed that the negative particles are all alike and smaller than atoms. Thomson concluded that the negative particles couldnt be fundamental units of matter because they are all alike. Instead, they must be parts of atoms. The negative particles were later named electrons. Thomson knew that atoms are neutral in electric charge. So how could atoms contain negative particles? Thomson thought that the rest of the atom must be positive to cancel out the negative charge. He said that an atom is like
|
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The history of the atom begins around 450 B.C. with a Greek philosopher named Democritus (see Figure 5.7). Democritus wondered what would happen if you cut a piece of matter, such as an apple, into smaller and smaller pieces. He thought that a point would be reached where matter could not be cut into still smaller pieces. He called these "uncuttable" pieces atomos. This is where the modern term atom comes from. Democritus was an important philosopher. However, he was less influential than the Greek philosopher Aristotle, who lived about 100 years after Democritus. Aristotle rejected Democrituss idea of atoms. In fact, Aristotle thought Around 1800, a British chemist named John Dalton revived Democrituss early ideas about the atom. Dalton is pictured in Figure 5.8. He made a living by teaching and just did research in his spare time. Nonetheless, from his research results, he developed one of the most important theories in science. Dalton did many experiments that provided evidence for atoms. For example, he studied the pressure of gases. He concluded that gases must consist of tiny particles in constant motion. Dalton also researched the properties of compounds. He showed that a compound always consists of the same elements in the same ratio. On the other hand, different compounds always consist of different elements or ratios. This can happen, Dalton reasoned, only if elements are made of tiny particles that can combine in an endless variety of ways. From his research, Dalton developed a theory of the atom. You can learn more about Dalton and his research by watching the video at this URL: (9:03). MEDIA Click image to the left or use the URL below. URL: The atomic theory Dalton developed consists of three ideas: All substances are made of atoms. Atoms are the smallest particles of matter. They cannot be divided into smaller particles. They also cannot be created or destroyed. All atoms of the same element are alike and have the same mass. Atoms of different elements are different and have different masses. Atoms join together to form compounds. A given compound always consists of the same kinds of atoms in the same ratio. Daltons theory was soon widely accepted. Most of it is still accepted today. The only part that is no longer accepted is his idea that atoms are the smallest particles. Scientists now know that atoms consist of even smaller particles. Dalton incorrectly thought that atoms are tiny solid particles of matter. He used solid wooden balls to model them. The sketch in the Figure 5.9 shows how Daltons model atoms looked. He made holes in the balls so they could be joined together with hooks. In this way, the balls could be used to model compounds. When later scientists discovered subatomic particles (particles smaller than the atom itself), they realized that Daltons models were too simple. They didnt show that atoms consist of even smaller particles. Models including these smaller particles were later developed. The next major advance in the history of the atom was the discovery of electrons. These were the first subatomic particles to be identified. They were discovered in 1897 by a British physicist named J. J. Thomson. You can learn more about Thomson and his discovery at this online exhibit: . Thomson was interested in electricity. He did experiments in which he passed an electric current through a vacuum tube. The experiments are described in Figure 5.10. Thomsons experiments showed that an electric current consists of flowing, negatively charged particles. Why was this discovery important? Many scientists of Thomsons time thought that electric current consists of rays, like rays of light, and that it is positive rather than negative. Thomsons experiments also showed that the negative particles are all alike and smaller than atoms. Thomson concluded that the negative particles couldnt be fundamental units of matter because they are all alike. Instead, they must be parts of atoms. The negative particles were later named electrons. Thomson knew that atoms are neutral in electric charge. So how could atoms contain negative particles? Thomson thought that the rest of the atom must be positive to cancel out the negative charge. He said that an atom is like
|
scientist who developed atomic theory
|
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The history of the atom begins around 450 B.C. with a Greek philosopher named Democritus (see Figure 5.7). Democritus wondered what would happen if you cut a piece of matter, such as an apple, into smaller and smaller pieces. He thought that a point would be reached where matter could not be cut into still smaller pieces. He called these "uncuttable" pieces atomos. This is where the modern term atom comes from. Democritus was an important philosopher. However, he was less influential than the Greek philosopher Aristotle, who lived about 100 years after Democritus. Aristotle rejected Democrituss idea of atoms. In fact, Aristotle thought Around 1800, a British chemist named John Dalton revived Democrituss early ideas about the atom. Dalton is pictured in Figure 5.8. He made a living by teaching and just did research in his spare time. Nonetheless, from his research results, he developed one of the most important theories in science. Dalton did many experiments that provided evidence for atoms. For example, he studied the pressure of gases. He concluded that gases must consist of tiny particles in constant motion. Dalton also researched the properties of compounds. He showed that a compound always consists of the same elements in the same ratio. On the other hand, different compounds always consist of different elements or ratios. This can happen, Dalton reasoned, only if elements are made of tiny particles that can combine in an endless variety of ways. From his research, Dalton developed a theory of the atom. You can learn more about Dalton and his research by watching the video at this URL: (9:03). MEDIA Click image to the left or use the URL below. URL: The atomic theory Dalton developed consists of three ideas: All substances are made of atoms. Atoms are the smallest particles of matter. They cannot be divided into smaller particles. They also cannot be created or destroyed. All atoms of the same element are alike and have the same mass. Atoms of different elements are different and have different masses. Atoms join together to form compounds. A given compound always consists of the same kinds of atoms in the same ratio. Daltons theory was soon widely accepted. Most of it is still accepted today. The only part that is no longer accepted is his idea that atoms are the smallest particles. Scientists now know that atoms consist of even smaller particles. Dalton incorrectly thought that atoms are tiny solid particles of matter. He used solid wooden balls to model them. The sketch in the Figure 5.9 shows how Daltons model atoms looked. He made holes in the balls so they could be joined together with hooks. In this way, the balls could be used to model compounds. When later scientists discovered subatomic particles (particles smaller than the atom itself), they realized that Daltons models were too simple. They didnt show that atoms consist of even smaller particles. Models including these smaller particles were later developed. The next major advance in the history of the atom was the discovery of electrons. These were the first subatomic particles to be identified. They were discovered in 1897 by a British physicist named J. J. Thomson. You can learn more about Thomson and his discovery at this online exhibit: . Thomson was interested in electricity. He did experiments in which he passed an electric current through a vacuum tube. The experiments are described in Figure 5.10. Thomsons experiments showed that an electric current consists of flowing, negatively charged particles. Why was this discovery important? Many scientists of Thomsons time thought that electric current consists of rays, like rays of light, and that it is positive rather than negative. Thomsons experiments also showed that the negative particles are all alike and smaller than atoms. Thomson concluded that the negative particles couldnt be fundamental units of matter because they are all alike. Instead, they must be parts of atoms. The negative particles were later named electrons. Thomson knew that atoms are neutral in electric charge. So how could atoms contain negative particles? Thomson thought that the rest of the atom must be positive to cancel out the negative charge. He said that an atom is like
|
Which statement is part of Daltons atomic theory?
|
[
"All substances are made of atoms."
] |
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|
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The history of the atom begins around 450 B.C. with a Greek philosopher named Democritus (see Figure 5.7). Democritus wondered what would happen if you cut a piece of matter, such as an apple, into smaller and smaller pieces. He thought that a point would be reached where matter could not be cut into still smaller pieces. He called these "uncuttable" pieces atomos. This is where the modern term atom comes from. Democritus was an important philosopher. However, he was less influential than the Greek philosopher Aristotle, who lived about 100 years after Democritus. Aristotle rejected Democrituss idea of atoms. In fact, Aristotle thought Around 1800, a British chemist named John Dalton revived Democrituss early ideas about the atom. Dalton is pictured in Figure 5.8. He made a living by teaching and just did research in his spare time. Nonetheless, from his research results, he developed one of the most important theories in science. Dalton did many experiments that provided evidence for atoms. For example, he studied the pressure of gases. He concluded that gases must consist of tiny particles in constant motion. Dalton also researched the properties of compounds. He showed that a compound always consists of the same elements in the same ratio. On the other hand, different compounds always consist of different elements or ratios. This can happen, Dalton reasoned, only if elements are made of tiny particles that can combine in an endless variety of ways. From his research, Dalton developed a theory of the atom. You can learn more about Dalton and his research by watching the video at this URL: (9:03). MEDIA Click image to the left or use the URL below. URL: The atomic theory Dalton developed consists of three ideas: All substances are made of atoms. Atoms are the smallest particles of matter. They cannot be divided into smaller particles. They also cannot be created or destroyed. All atoms of the same element are alike and have the same mass. Atoms of different elements are different and have different masses. Atoms join together to form compounds. A given compound always consists of the same kinds of atoms in the same ratio. Daltons theory was soon widely accepted. Most of it is still accepted today. The only part that is no longer accepted is his idea that atoms are the smallest particles. Scientists now know that atoms consist of even smaller particles. Dalton incorrectly thought that atoms are tiny solid particles of matter. He used solid wooden balls to model them. The sketch in the Figure 5.9 shows how Daltons model atoms looked. He made holes in the balls so they could be joined together with hooks. In this way, the balls could be used to model compounds. When later scientists discovered subatomic particles (particles smaller than the atom itself), they realized that Daltons models were too simple. They didnt show that atoms consist of even smaller particles. Models including these smaller particles were later developed. The next major advance in the history of the atom was the discovery of electrons. These were the first subatomic particles to be identified. They were discovered in 1897 by a British physicist named J. J. Thomson. You can learn more about Thomson and his discovery at this online exhibit: . Thomson was interested in electricity. He did experiments in which he passed an electric current through a vacuum tube. The experiments are described in Figure 5.10. Thomsons experiments showed that an electric current consists of flowing, negatively charged particles. Why was this discovery important? Many scientists of Thomsons time thought that electric current consists of rays, like rays of light, and that it is positive rather than negative. Thomsons experiments also showed that the negative particles are all alike and smaller than atoms. Thomson concluded that the negative particles couldnt be fundamental units of matter because they are all alike. Instead, they must be parts of atoms. The negative particles were later named electrons. Thomson knew that atoms are neutral in electric charge. So how could atoms contain negative particles? Thomson thought that the rest of the atom must be positive to cancel out the negative charge. He said that an atom is like
|
In the plum pudding model of the atom, the plums represent
|
[
"electrons."
] |
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The history of the atom begins around 450 B.C. with a Greek philosopher named Democritus (see Figure 5.7). Democritus wondered what would happen if you cut a piece of matter, such as an apple, into smaller and smaller pieces. He thought that a point would be reached where matter could not be cut into still smaller pieces. He called these "uncuttable" pieces atomos. This is where the modern term atom comes from. Democritus was an important philosopher. However, he was less influential than the Greek philosopher Aristotle, who lived about 100 years after Democritus. Aristotle rejected Democrituss idea of atoms. In fact, Aristotle thought Around 1800, a British chemist named John Dalton revived Democrituss early ideas about the atom. Dalton is pictured in Figure 5.8. He made a living by teaching and just did research in his spare time. Nonetheless, from his research results, he developed one of the most important theories in science. Dalton did many experiments that provided evidence for atoms. For example, he studied the pressure of gases. He concluded that gases must consist of tiny particles in constant motion. Dalton also researched the properties of compounds. He showed that a compound always consists of the same elements in the same ratio. On the other hand, different compounds always consist of different elements or ratios. This can happen, Dalton reasoned, only if elements are made of tiny particles that can combine in an endless variety of ways. From his research, Dalton developed a theory of the atom. You can learn more about Dalton and his research by watching the video at this URL: (9:03). MEDIA Click image to the left or use the URL below. URL: The atomic theory Dalton developed consists of three ideas: All substances are made of atoms. Atoms are the smallest particles of matter. They cannot be divided into smaller particles. They also cannot be created or destroyed. All atoms of the same element are alike and have the same mass. Atoms of different elements are different and have different masses. Atoms join together to form compounds. A given compound always consists of the same kinds of atoms in the same ratio. Daltons theory was soon widely accepted. Most of it is still accepted today. The only part that is no longer accepted is his idea that atoms are the smallest particles. Scientists now know that atoms consist of even smaller particles. Dalton incorrectly thought that atoms are tiny solid particles of matter. He used solid wooden balls to model them. The sketch in the Figure 5.9 shows how Daltons model atoms looked. He made holes in the balls so they could be joined together with hooks. In this way, the balls could be used to model compounds. When later scientists discovered subatomic particles (particles smaller than the atom itself), they realized that Daltons models were too simple. They didnt show that atoms consist of even smaller particles. Models including these smaller particles were later developed. The next major advance in the history of the atom was the discovery of electrons. These were the first subatomic particles to be identified. They were discovered in 1897 by a British physicist named J. J. Thomson. You can learn more about Thomson and his discovery at this online exhibit: . Thomson was interested in electricity. He did experiments in which he passed an electric current through a vacuum tube. The experiments are described in Figure 5.10. Thomsons experiments showed that an electric current consists of flowing, negatively charged particles. Why was this discovery important? Many scientists of Thomsons time thought that electric current consists of rays, like rays of light, and that it is positive rather than negative. Thomsons experiments also showed that the negative particles are all alike and smaller than atoms. Thomson concluded that the negative particles couldnt be fundamental units of matter because they are all alike. Instead, they must be parts of atoms. The negative particles were later named electrons. Thomson knew that atoms are neutral in electric charge. So how could atoms contain negative particles? Thomson thought that the rest of the atom must be positive to cancel out the negative charge. He said that an atom is like
|
In the planetary model, the planets represent
|
[
"electrons."
] |
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|
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Not everyone had the same warning the people on Tillys beach had. The Boxing Day Tsunami of December 26, 2004 was by far the deadliest of all time (Figure 1.1). The tsunami was caused by the 2004 Indian Ocean Earthquake. With a magnitude of 9.2, it was the second largest earthquake ever recorded. The extreme movement of the crust displaced trillions of tons of water along the entire length of the rupture. Several tsunami waves were created with about 30 minutes between the peaks of each one. The waves that struck nearby Sumatra 15 minutes after the quake reached more than 10 meters (33 feet) in height. The size of the waves decreased with distance from the earthquake and were about 4 meters (13 feet) high in Somalia. The tsunami did so much damage because it traveled throughout the Indian Ocean. About 230,000 people died in eight countries. There were fatalities even as far away as South Africa, nearly 8,000 kilometers (5,000 miles) from the earthquake epicenter. More than 1.2 million people lost their homes and many more lost their ways of making a living. The countries that were most affected by the 2004 Boxing Day tsunami. The Japanese received a one-two punch in March 2011. The 2011 Tohoku earthquake offshore was a magnitude 9.0 and damage from the quake was extensive. People didnt have time to recover before massive tsunami waves hit the island nation. As seen in Figure 1.2, waves in some regions topped 9 meters (27 feet). The tsunami did much more damage than the massive earthquake (Figure 1.3). Worst was the damage done to nuclear power plants along the northeastern coast. Eleven reactors were automatically shut down. Power and backup power were lost at the Fukushima plant, leading to equipment failures, meltdowns, and the release of radioactive materials. Control and cleanup of the disabled plants will go on for many years. As a result of the 2004 tsunami, an Indian Ocean warning system was put into operation in June 2006. Prior to 2004, no one had thought a large tsunami was possible in the Indian Ocean. In comparison, a warning system has been in effect around the Pacific Ocean for more than 50 years. The system was used to warn of possible tsunami waves after the Tohoku earthquake, but most were too close to the quake to get to high ground in time. Further away, people were evacuated along many Pacific coastlines, but the waves were not that large.
|
the 2004 boxing day tsunami killed people all around this ocean basin
|
[
"indian ocean"
] |
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Not everyone had the same warning the people on Tillys beach had. The Boxing Day Tsunami of December 26, 2004 was by far the deadliest of all time (Figure 1.1). The tsunami was caused by the 2004 Indian Ocean Earthquake. With a magnitude of 9.2, it was the second largest earthquake ever recorded. The extreme movement of the crust displaced trillions of tons of water along the entire length of the rupture. Several tsunami waves were created with about 30 minutes between the peaks of each one. The waves that struck nearby Sumatra 15 minutes after the quake reached more than 10 meters (33 feet) in height. The size of the waves decreased with distance from the earthquake and were about 4 meters (13 feet) high in Somalia. The tsunami did so much damage because it traveled throughout the Indian Ocean. About 230,000 people died in eight countries. There were fatalities even as far away as South Africa, nearly 8,000 kilometers (5,000 miles) from the earthquake epicenter. More than 1.2 million people lost their homes and many more lost their ways of making a living. The countries that were most affected by the 2004 Boxing Day tsunami. The Japanese received a one-two punch in March 2011. The 2011 Tohoku earthquake offshore was a magnitude 9.0 and damage from the quake was extensive. People didnt have time to recover before massive tsunami waves hit the island nation. As seen in Figure 1.2, waves in some regions topped 9 meters (27 feet). The tsunami did much more damage than the massive earthquake (Figure 1.3). Worst was the damage done to nuclear power plants along the northeastern coast. Eleven reactors were automatically shut down. Power and backup power were lost at the Fukushima plant, leading to equipment failures, meltdowns, and the release of radioactive materials. Control and cleanup of the disabled plants will go on for many years. As a result of the 2004 tsunami, an Indian Ocean warning system was put into operation in June 2006. Prior to 2004, no one had thought a large tsunami was possible in the Indian Ocean. In comparison, a warning system has been in effect around the Pacific Ocean for more than 50 years. The system was used to warn of possible tsunami waves after the Tohoku earthquake, but most were too close to the quake to get to high ground in time. Further away, people were evacuated along many Pacific coastlines, but the waves were not that large.
|
the magnitude of the earthquake that caused the boxing day tsunami of 2004 was
|
[
"9.2"
] |
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Humidity is the amount of water vapor in the air in a particular spot. We usually use the term to mean relative humidity, the percentage of water vapor a certain volume of air is holding relative to the maximum amount it can contain. If the humidity today is 80%, it means that the air contains 80% of the total amount of water it can hold at that temperature. What will happen if the humidity increases to more than 100%? The excess water condenses and forms precipitation. Since warm air can hold more water vapor than cool air, raising or lowering temperature can change airs relative humidity (Figure 1.1). The temperature at which air becomes saturated with water is called the airs dew point. This term makes sense, because water condenses from the air as dew if the air cools down overnight and reaches 100% humidity. This diagram shows the amount of water air can hold at different temperatures. The temperatures are given in degrees Cel- sius. Water vapor is not visible unless it condenses to become a cloud. Water vapor condenses around a nucleus, such as dust, smoke, or a salt crystal. This forms a tiny liquid droplet. Billions of these water droplets together make a cloud. Clouds form when air reaches its dew point. This can happen in two ways: (1) Air temperature stays the same but humidity increases. This is common in locations that are warm and humid. (2) Humidity remains the same, but temperature decreases. When the air cools enough to reach 100% humidity, water droplets form. Air cools when it comes into contact with a cold surface or when it rises. Rising air creates clouds when it has been warmed at or near the ground level and then is pushed up over a mountain or mountain range or is thrust over a mass of cold, dense air. Click image to the left or use the URL below. URL: Clouds have a big influence on weather: by preventing solar radiation from reaching the ground. by absorbing warmth that is re-emitted from the ground. as the source of precipitation. When there are no clouds, there is less insulation. As a result, cloudless days can be extremely hot, and cloudless nights can be very cold. For this reason, cloudy days tend to have a lower range of temperatures than clear days. Clouds are classified in several ways. The most common classification used today divides clouds into four separate cloud groups, which are determined by their altitude (Figure 1.2). The four cloud types and where they are found in the atmosphere. High clouds form from ice crystals where the air is extremely cold and can hold little water vapor. Cirrus, cirrostratus, and cirrocumulus are all names of high clouds. Middle clouds, including altocumulus and altostratus clouds, may be made of water droplets, ice crystals or both, depending on the air temperatures. Thick and broad altostratus clouds are gray or blue-gray. They often cover the entire sky and usually mean a large storm, bearing a lot of precipitation, is coming. Low clouds are nearly all water droplets. Stratus, stratocumulus, and nimbostratus clouds are common low clouds. Nimbostratus clouds are thick and dark. They bring steady rain or snow. Vertical clouds, clouds with the prefix "cumulo-," grow vertically instead of horizontally and have their bases at low altitude and their tops at high or middle altitude. Clouds grow vertically when strong air currents are rising upward. Precipitating clouds are nimbus clouds. Fog (Figure 1.3) is a cloud located at or near the ground . When humid air near the ground cools below its dew point, fog is formed. Each type of fog forms in a different way. Radiation fog forms at night when skies are clear and the relative humidity is high. As the ground cools, the bottom layer of air cools below its dew point. Tule fog is an extreme form of radiation fog found in some regions. San Francisco, California, is famous for its summertime advection fog. Warm, moist Pacific Ocean air blows over the cold California current and cools below its dew point. Sea breezes bring the fog
|
clouds are classified by
|
[
"altitude"
] |
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We now know how variation in traits is inherited. Variation in traits is controlled by different alleles for genes. Alleles, in turn, are passed to gametes and then to offspring. Evolution occurs because of changes in alleles over time. How long a time? That depends on the time scale of evolution you consider. Evolution that occurs over a short period of time is known as microevolution. It might take place in just a couple of generations. This scale of evolution occurs at the level of the population. The Grants observed evolution at this scale in populations of Darwins finches. Beak size in finch populations changed in just two years because of a serious drought. Evolution that occurs over a long period of time is called macroevolution. It might take place over millions of years. This scale of evolution occurs above the level of the species. Fossils provide evidence for evolution at this scale. The evolution of the horse family, shown in Figure 7.13, is an example of macroevolution. Individuals dont evolve. Their alleles dont change over time. The unit of microevolution is the population. A population is a group of organisms of the same species that live in the same area. All the genes in all the members of a population make up the populations gene pool. For each gene, the gene pool includes all the different alleles in the population. The gene pool can be described by its allele frequencies for specific genes. The frequency of an allele is the number of copies of that allele divided by the total number of alleles for the gene in the gene pool. A simple example will help you understand these concepts. The data in Table 7.2 represent a population of 100 individuals. For each gene, the gene pool has a total of 200 alleles (2 per individual x 100 individuals). The gene in question exists as two different alleles, A and a. The number of A alleles in the gene pool is 140. Of these, 100 are in the 50 AA homozygotes. Another 40 are in the 40 Aa heterozygotes. The number of a alleles in the gene pool is 60. Of these, 40 are in the 40 Aa heterozygotes. Another 20 are in the 10 aa homozygotes. The frequency of the A allele is 140/200 = 0.7. The frequency of the a allele is 60/200 = 0.3. Genotype AA Aa aa Totals Number of Individuals 50 40 10 100 Number of A Alleles 100 (50 x 2) 40 (40 x 1) 0 (10 x 0) 140 Number of a Alleles 0 (50 x 0) 40 (40 x 1) 20 (10 x 2) 60 Evolution occurs in a population when its allele frequencies change over time. For example, the frequency of the A allele might change from 0.7 to 0.8. If that happens, evolution has occurred. What causes allele frequencies to change? The answer is forces of evolution. There are four major forces of evolution that cause allele frequencies to change. They are mutation, gene flow, genetic drift, and natural selection. Mutation creates new genetic variation in a gene pool This is how all new alleles first arise. Its the ultimate source of new genetic variation, so it is essential for evolution. However, for any given gene, the chance of a mutation occurring is very small. Therefore, mutation alone does not have much effect on allele frequencies. Gene flow is the movement of genes into or out of a gene pool It occurs when individuals migrate into or out of the population. How much gene flow changes allele frequencies depends on how many migrants there are and their genotypes. Genetic drift is a random change in allele frequencies. It occurs in small populations. Allele frequencies in the offspring may differ by chance from those in the parents. This is like tossing a coin just a few times. You may, by chance, get more or less than the expected 50 percent heads or tails. In the same way, you may get more or less than the expected allele frequencies in the small number of individuals in the next generation. The smaller the population is, the more allele frequencies may drift. Natural selection is a change in
|
___all the genes in all the members of a population
|
[
"gene pool"
] |
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We now know how variation in traits is inherited. Variation in traits is controlled by different alleles for genes. Alleles, in turn, are passed to gametes and then to offspring. Evolution occurs because of changes in alleles over time. How long a time? That depends on the time scale of evolution you consider. Evolution that occurs over a short period of time is known as microevolution. It might take place in just a couple of generations. This scale of evolution occurs at the level of the population. The Grants observed evolution at this scale in populations of Darwins finches. Beak size in finch populations changed in just two years because of a serious drought. Evolution that occurs over a long period of time is called macroevolution. It might take place over millions of years. This scale of evolution occurs above the level of the species. Fossils provide evidence for evolution at this scale. The evolution of the horse family, shown in Figure 7.13, is an example of macroevolution. Individuals dont evolve. Their alleles dont change over time. The unit of microevolution is the population. A population is a group of organisms of the same species that live in the same area. All the genes in all the members of a population make up the populations gene pool. For each gene, the gene pool includes all the different alleles in the population. The gene pool can be described by its allele frequencies for specific genes. The frequency of an allele is the number of copies of that allele divided by the total number of alleles for the gene in the gene pool. A simple example will help you understand these concepts. The data in Table 7.2 represent a population of 100 individuals. For each gene, the gene pool has a total of 200 alleles (2 per individual x 100 individuals). The gene in question exists as two different alleles, A and a. The number of A alleles in the gene pool is 140. Of these, 100 are in the 50 AA homozygotes. Another 40 are in the 40 Aa heterozygotes. The number of a alleles in the gene pool is 60. Of these, 40 are in the 40 Aa heterozygotes. Another 20 are in the 10 aa homozygotes. The frequency of the A allele is 140/200 = 0.7. The frequency of the a allele is 60/200 = 0.3. Genotype AA Aa aa Totals Number of Individuals 50 40 10 100 Number of A Alleles 100 (50 x 2) 40 (40 x 1) 0 (10 x 0) 140 Number of a Alleles 0 (50 x 0) 40 (40 x 1) 20 (10 x 2) 60 Evolution occurs in a population when its allele frequencies change over time. For example, the frequency of the A allele might change from 0.7 to 0.8. If that happens, evolution has occurred. What causes allele frequencies to change? The answer is forces of evolution. There are four major forces of evolution that cause allele frequencies to change. They are mutation, gene flow, genetic drift, and natural selection. Mutation creates new genetic variation in a gene pool This is how all new alleles first arise. Its the ultimate source of new genetic variation, so it is essential for evolution. However, for any given gene, the chance of a mutation occurring is very small. Therefore, mutation alone does not have much effect on allele frequencies. Gene flow is the movement of genes into or out of a gene pool It occurs when individuals migrate into or out of the population. How much gene flow changes allele frequencies depends on how many migrants there are and their genotypes. Genetic drift is a random change in allele frequencies. It occurs in small populations. Allele frequencies in the offspring may differ by chance from those in the parents. This is like tossing a coin just a few times. You may, by chance, get more or less than the expected 50 percent heads or tails. In the same way, you may get more or less than the expected allele frequencies in the small number of individuals in the next generation. The smaller the population is, the more allele frequencies may drift. Natural selection is a change in
|
___random change in a small populations allele frequencies
|
[
"genetic drift"
] |
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We now know how variation in traits is inherited. Variation in traits is controlled by different alleles for genes. Alleles, in turn, are passed to gametes and then to offspring. Evolution occurs because of changes in alleles over time. How long a time? That depends on the time scale of evolution you consider. Evolution that occurs over a short period of time is known as microevolution. It might take place in just a couple of generations. This scale of evolution occurs at the level of the population. The Grants observed evolution at this scale in populations of Darwins finches. Beak size in finch populations changed in just two years because of a serious drought. Evolution that occurs over a long period of time is called macroevolution. It might take place over millions of years. This scale of evolution occurs above the level of the species. Fossils provide evidence for evolution at this scale. The evolution of the horse family, shown in Figure 7.13, is an example of macroevolution. Individuals dont evolve. Their alleles dont change over time. The unit of microevolution is the population. A population is a group of organisms of the same species that live in the same area. All the genes in all the members of a population make up the populations gene pool. For each gene, the gene pool includes all the different alleles in the population. The gene pool can be described by its allele frequencies for specific genes. The frequency of an allele is the number of copies of that allele divided by the total number of alleles for the gene in the gene pool. A simple example will help you understand these concepts. The data in Table 7.2 represent a population of 100 individuals. For each gene, the gene pool has a total of 200 alleles (2 per individual x 100 individuals). The gene in question exists as two different alleles, A and a. The number of A alleles in the gene pool is 140. Of these, 100 are in the 50 AA homozygotes. Another 40 are in the 40 Aa heterozygotes. The number of a alleles in the gene pool is 60. Of these, 40 are in the 40 Aa heterozygotes. Another 20 are in the 10 aa homozygotes. The frequency of the A allele is 140/200 = 0.7. The frequency of the a allele is 60/200 = 0.3. Genotype AA Aa aa Totals Number of Individuals 50 40 10 100 Number of A Alleles 100 (50 x 2) 40 (40 x 1) 0 (10 x 0) 140 Number of a Alleles 0 (50 x 0) 40 (40 x 1) 20 (10 x 2) 60 Evolution occurs in a population when its allele frequencies change over time. For example, the frequency of the A allele might change from 0.7 to 0.8. If that happens, evolution has occurred. What causes allele frequencies to change? The answer is forces of evolution. There are four major forces of evolution that cause allele frequencies to change. They are mutation, gene flow, genetic drift, and natural selection. Mutation creates new genetic variation in a gene pool This is how all new alleles first arise. Its the ultimate source of new genetic variation, so it is essential for evolution. However, for any given gene, the chance of a mutation occurring is very small. Therefore, mutation alone does not have much effect on allele frequencies. Gene flow is the movement of genes into or out of a gene pool It occurs when individuals migrate into or out of the population. How much gene flow changes allele frequencies depends on how many migrants there are and their genotypes. Genetic drift is a random change in allele frequencies. It occurs in small populations. Allele frequencies in the offspring may differ by chance from those in the parents. This is like tossing a coin just a few times. You may, by chance, get more or less than the expected 50 percent heads or tails. In the same way, you may get more or less than the expected allele frequencies in the small number of individuals in the next generation. The smaller the population is, the more allele frequencies may drift. Natural selection is a change in
|
___change in allele frequencies that occurs because some genotypes are more fit than others
|
[
"natural selection"
] |
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}
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We now know how variation in traits is inherited. Variation in traits is controlled by different alleles for genes. Alleles, in turn, are passed to gametes and then to offspring. Evolution occurs because of changes in alleles over time. How long a time? That depends on the time scale of evolution you consider. Evolution that occurs over a short period of time is known as microevolution. It might take place in just a couple of generations. This scale of evolution occurs at the level of the population. The Grants observed evolution at this scale in populations of Darwins finches. Beak size in finch populations changed in just two years because of a serious drought. Evolution that occurs over a long period of time is called macroevolution. It might take place over millions of years. This scale of evolution occurs above the level of the species. Fossils provide evidence for evolution at this scale. The evolution of the horse family, shown in Figure 7.13, is an example of macroevolution. Individuals dont evolve. Their alleles dont change over time. The unit of microevolution is the population. A population is a group of organisms of the same species that live in the same area. All the genes in all the members of a population make up the populations gene pool. For each gene, the gene pool includes all the different alleles in the population. The gene pool can be described by its allele frequencies for specific genes. The frequency of an allele is the number of copies of that allele divided by the total number of alleles for the gene in the gene pool. A simple example will help you understand these concepts. The data in Table 7.2 represent a population of 100 individuals. For each gene, the gene pool has a total of 200 alleles (2 per individual x 100 individuals). The gene in question exists as two different alleles, A and a. The number of A alleles in the gene pool is 140. Of these, 100 are in the 50 AA homozygotes. Another 40 are in the 40 Aa heterozygotes. The number of a alleles in the gene pool is 60. Of these, 40 are in the 40 Aa heterozygotes. Another 20 are in the 10 aa homozygotes. The frequency of the A allele is 140/200 = 0.7. The frequency of the a allele is 60/200 = 0.3. Genotype AA Aa aa Totals Number of Individuals 50 40 10 100 Number of A Alleles 100 (50 x 2) 40 (40 x 1) 0 (10 x 0) 140 Number of a Alleles 0 (50 x 0) 40 (40 x 1) 20 (10 x 2) 60 Evolution occurs in a population when its allele frequencies change over time. For example, the frequency of the A allele might change from 0.7 to 0.8. If that happens, evolution has occurred. What causes allele frequencies to change? The answer is forces of evolution. There are four major forces of evolution that cause allele frequencies to change. They are mutation, gene flow, genetic drift, and natural selection. Mutation creates new genetic variation in a gene pool This is how all new alleles first arise. Its the ultimate source of new genetic variation, so it is essential for evolution. However, for any given gene, the chance of a mutation occurring is very small. Therefore, mutation alone does not have much effect on allele frequencies. Gene flow is the movement of genes into or out of a gene pool It occurs when individuals migrate into or out of the population. How much gene flow changes allele frequencies depends on how many migrants there are and their genotypes. Genetic drift is a random change in allele frequencies. It occurs in small populations. Allele frequencies in the offspring may differ by chance from those in the parents. This is like tossing a coin just a few times. You may, by chance, get more or less than the expected 50 percent heads or tails. In the same way, you may get more or less than the expected allele frequencies in the small number of individuals in the next generation. The smaller the population is, the more allele frequencies may drift. Natural selection is a change in
|
The ultimate source of new genetic variation is
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[
"mutation"
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We now know how variation in traits is inherited. Variation in traits is controlled by different alleles for genes. Alleles, in turn, are passed to gametes and then to offspring. Evolution occurs because of changes in alleles over time. How long a time? That depends on the time scale of evolution you consider. Evolution that occurs over a short period of time is known as microevolution. It might take place in just a couple of generations. This scale of evolution occurs at the level of the population. The Grants observed evolution at this scale in populations of Darwins finches. Beak size in finch populations changed in just two years because of a serious drought. Evolution that occurs over a long period of time is called macroevolution. It might take place over millions of years. This scale of evolution occurs above the level of the species. Fossils provide evidence for evolution at this scale. The evolution of the horse family, shown in Figure 7.13, is an example of macroevolution. Individuals dont evolve. Their alleles dont change over time. The unit of microevolution is the population. A population is a group of organisms of the same species that live in the same area. All the genes in all the members of a population make up the populations gene pool. For each gene, the gene pool includes all the different alleles in the population. The gene pool can be described by its allele frequencies for specific genes. The frequency of an allele is the number of copies of that allele divided by the total number of alleles for the gene in the gene pool. A simple example will help you understand these concepts. The data in Table 7.2 represent a population of 100 individuals. For each gene, the gene pool has a total of 200 alleles (2 per individual x 100 individuals). The gene in question exists as two different alleles, A and a. The number of A alleles in the gene pool is 140. Of these, 100 are in the 50 AA homozygotes. Another 40 are in the 40 Aa heterozygotes. The number of a alleles in the gene pool is 60. Of these, 40 are in the 40 Aa heterozygotes. Another 20 are in the 10 aa homozygotes. The frequency of the A allele is 140/200 = 0.7. The frequency of the a allele is 60/200 = 0.3. Genotype AA Aa aa Totals Number of Individuals 50 40 10 100 Number of A Alleles 100 (50 x 2) 40 (40 x 1) 0 (10 x 0) 140 Number of a Alleles 0 (50 x 0) 40 (40 x 1) 20 (10 x 2) 60 Evolution occurs in a population when its allele frequencies change over time. For example, the frequency of the A allele might change from 0.7 to 0.8. If that happens, evolution has occurred. What causes allele frequencies to change? The answer is forces of evolution. There are four major forces of evolution that cause allele frequencies to change. They are mutation, gene flow, genetic drift, and natural selection. Mutation creates new genetic variation in a gene pool This is how all new alleles first arise. Its the ultimate source of new genetic variation, so it is essential for evolution. However, for any given gene, the chance of a mutation occurring is very small. Therefore, mutation alone does not have much effect on allele frequencies. Gene flow is the movement of genes into or out of a gene pool It occurs when individuals migrate into or out of the population. How much gene flow changes allele frequencies depends on how many migrants there are and their genotypes. Genetic drift is a random change in allele frequencies. It occurs in small populations. Allele frequencies in the offspring may differ by chance from those in the parents. This is like tossing a coin just a few times. You may, by chance, get more or less than the expected 50 percent heads or tails. In the same way, you may get more or less than the expected allele frequencies in the small number of individuals in the next generation. The smaller the population is, the more allele frequencies may drift. Natural selection is a change in
|
___group of organisms of the same species that live in the same area
|
[
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We now know how variation in traits is inherited. Variation in traits is controlled by different alleles for genes. Alleles, in turn, are passed to gametes and then to offspring. Evolution occurs because of changes in alleles over time. How long a time? That depends on the time scale of evolution you consider. Evolution that occurs over a short period of time is known as microevolution. It might take place in just a couple of generations. This scale of evolution occurs at the level of the population. The Grants observed evolution at this scale in populations of Darwins finches. Beak size in finch populations changed in just two years because of a serious drought. Evolution that occurs over a long period of time is called macroevolution. It might take place over millions of years. This scale of evolution occurs above the level of the species. Fossils provide evidence for evolution at this scale. The evolution of the horse family, shown in Figure 7.13, is an example of macroevolution. Individuals dont evolve. Their alleles dont change over time. The unit of microevolution is the population. A population is a group of organisms of the same species that live in the same area. All the genes in all the members of a population make up the populations gene pool. For each gene, the gene pool includes all the different alleles in the population. The gene pool can be described by its allele frequencies for specific genes. The frequency of an allele is the number of copies of that allele divided by the total number of alleles for the gene in the gene pool. A simple example will help you understand these concepts. The data in Table 7.2 represent a population of 100 individuals. For each gene, the gene pool has a total of 200 alleles (2 per individual x 100 individuals). The gene in question exists as two different alleles, A and a. The number of A alleles in the gene pool is 140. Of these, 100 are in the 50 AA homozygotes. Another 40 are in the 40 Aa heterozygotes. The number of a alleles in the gene pool is 60. Of these, 40 are in the 40 Aa heterozygotes. Another 20 are in the 10 aa homozygotes. The frequency of the A allele is 140/200 = 0.7. The frequency of the a allele is 60/200 = 0.3. Genotype AA Aa aa Totals Number of Individuals 50 40 10 100 Number of A Alleles 100 (50 x 2) 40 (40 x 1) 0 (10 x 0) 140 Number of a Alleles 0 (50 x 0) 40 (40 x 1) 20 (10 x 2) 60 Evolution occurs in a population when its allele frequencies change over time. For example, the frequency of the A allele might change from 0.7 to 0.8. If that happens, evolution has occurred. What causes allele frequencies to change? The answer is forces of evolution. There are four major forces of evolution that cause allele frequencies to change. They are mutation, gene flow, genetic drift, and natural selection. Mutation creates new genetic variation in a gene pool This is how all new alleles first arise. Its the ultimate source of new genetic variation, so it is essential for evolution. However, for any given gene, the chance of a mutation occurring is very small. Therefore, mutation alone does not have much effect on allele frequencies. Gene flow is the movement of genes into or out of a gene pool It occurs when individuals migrate into or out of the population. How much gene flow changes allele frequencies depends on how many migrants there are and their genotypes. Genetic drift is a random change in allele frequencies. It occurs in small populations. Allele frequencies in the offspring may differ by chance from those in the parents. This is like tossing a coin just a few times. You may, by chance, get more or less than the expected 50 percent heads or tails. In the same way, you may get more or less than the expected allele frequencies in the small number of individuals in the next generation. The smaller the population is, the more allele frequencies may drift. Natural selection is a change in
|
___movement of genes into or out of a population
|
[
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|
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We now know how variation in traits is inherited. Variation in traits is controlled by different alleles for genes. Alleles, in turn, are passed to gametes and then to offspring. Evolution occurs because of changes in alleles over time. How long a time? That depends on the time scale of evolution you consider. Evolution that occurs over a short period of time is known as microevolution. It might take place in just a couple of generations. This scale of evolution occurs at the level of the population. The Grants observed evolution at this scale in populations of Darwins finches. Beak size in finch populations changed in just two years because of a serious drought. Evolution that occurs over a long period of time is called macroevolution. It might take place over millions of years. This scale of evolution occurs above the level of the species. Fossils provide evidence for evolution at this scale. The evolution of the horse family, shown in Figure 7.13, is an example of macroevolution. Individuals dont evolve. Their alleles dont change over time. The unit of microevolution is the population. A population is a group of organisms of the same species that live in the same area. All the genes in all the members of a population make up the populations gene pool. For each gene, the gene pool includes all the different alleles in the population. The gene pool can be described by its allele frequencies for specific genes. The frequency of an allele is the number of copies of that allele divided by the total number of alleles for the gene in the gene pool. A simple example will help you understand these concepts. The data in Table 7.2 represent a population of 100 individuals. For each gene, the gene pool has a total of 200 alleles (2 per individual x 100 individuals). The gene in question exists as two different alleles, A and a. The number of A alleles in the gene pool is 140. Of these, 100 are in the 50 AA homozygotes. Another 40 are in the 40 Aa heterozygotes. The number of a alleles in the gene pool is 60. Of these, 40 are in the 40 Aa heterozygotes. Another 20 are in the 10 aa homozygotes. The frequency of the A allele is 140/200 = 0.7. The frequency of the a allele is 60/200 = 0.3. Genotype AA Aa aa Totals Number of Individuals 50 40 10 100 Number of A Alleles 100 (50 x 2) 40 (40 x 1) 0 (10 x 0) 140 Number of a Alleles 0 (50 x 0) 40 (40 x 1) 20 (10 x 2) 60 Evolution occurs in a population when its allele frequencies change over time. For example, the frequency of the A allele might change from 0.7 to 0.8. If that happens, evolution has occurred. What causes allele frequencies to change? The answer is forces of evolution. There are four major forces of evolution that cause allele frequencies to change. They are mutation, gene flow, genetic drift, and natural selection. Mutation creates new genetic variation in a gene pool This is how all new alleles first arise. Its the ultimate source of new genetic variation, so it is essential for evolution. However, for any given gene, the chance of a mutation occurring is very small. Therefore, mutation alone does not have much effect on allele frequencies. Gene flow is the movement of genes into or out of a gene pool It occurs when individuals migrate into or out of the population. How much gene flow changes allele frequencies depends on how many migrants there are and their genotypes. Genetic drift is a random change in allele frequencies. It occurs in small populations. Allele frequencies in the offspring may differ by chance from those in the parents. This is like tossing a coin just a few times. You may, by chance, get more or less than the expected 50 percent heads or tails. In the same way, you may get more or less than the expected allele frequencies in the small number of individuals in the next generation. The smaller the population is, the more allele frequencies may drift. Natural selection is a change in
|
Darwin thought that evolution occurs by
|
[
"natural selection"
] |
0bd0c1c920134b3aa9d4ba51f595e870
|
[
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We now know how variation in traits is inherited. Variation in traits is controlled by different alleles for genes. Alleles, in turn, are passed to gametes and then to offspring. Evolution occurs because of changes in alleles over time. How long a time? That depends on the time scale of evolution you consider. Evolution that occurs over a short period of time is known as microevolution. It might take place in just a couple of generations. This scale of evolution occurs at the level of the population. The Grants observed evolution at this scale in populations of Darwins finches. Beak size in finch populations changed in just two years because of a serious drought. Evolution that occurs over a long period of time is called macroevolution. It might take place over millions of years. This scale of evolution occurs above the level of the species. Fossils provide evidence for evolution at this scale. The evolution of the horse family, shown in Figure 7.13, is an example of macroevolution. Individuals dont evolve. Their alleles dont change over time. The unit of microevolution is the population. A population is a group of organisms of the same species that live in the same area. All the genes in all the members of a population make up the populations gene pool. For each gene, the gene pool includes all the different alleles in the population. The gene pool can be described by its allele frequencies for specific genes. The frequency of an allele is the number of copies of that allele divided by the total number of alleles for the gene in the gene pool. A simple example will help you understand these concepts. The data in Table 7.2 represent a population of 100 individuals. For each gene, the gene pool has a total of 200 alleles (2 per individual x 100 individuals). The gene in question exists as two different alleles, A and a. The number of A alleles in the gene pool is 140. Of these, 100 are in the 50 AA homozygotes. Another 40 are in the 40 Aa heterozygotes. The number of a alleles in the gene pool is 60. Of these, 40 are in the 40 Aa heterozygotes. Another 20 are in the 10 aa homozygotes. The frequency of the A allele is 140/200 = 0.7. The frequency of the a allele is 60/200 = 0.3. Genotype AA Aa aa Totals Number of Individuals 50 40 10 100 Number of A Alleles 100 (50 x 2) 40 (40 x 1) 0 (10 x 0) 140 Number of a Alleles 0 (50 x 0) 40 (40 x 1) 20 (10 x 2) 60 Evolution occurs in a population when its allele frequencies change over time. For example, the frequency of the A allele might change from 0.7 to 0.8. If that happens, evolution has occurred. What causes allele frequencies to change? The answer is forces of evolution. There are four major forces of evolution that cause allele frequencies to change. They are mutation, gene flow, genetic drift, and natural selection. Mutation creates new genetic variation in a gene pool This is how all new alleles first arise. Its the ultimate source of new genetic variation, so it is essential for evolution. However, for any given gene, the chance of a mutation occurring is very small. Therefore, mutation alone does not have much effect on allele frequencies. Gene flow is the movement of genes into or out of a gene pool It occurs when individuals migrate into or out of the population. How much gene flow changes allele frequencies depends on how many migrants there are and their genotypes. Genetic drift is a random change in allele frequencies. It occurs in small populations. Allele frequencies in the offspring may differ by chance from those in the parents. This is like tossing a coin just a few times. You may, by chance, get more or less than the expected 50 percent heads or tails. In the same way, you may get more or less than the expected allele frequencies in the small number of individuals in the next generation. The smaller the population is, the more allele frequencies may drift. Natural selection is a change in
|
A group of organisms that can mate and produce fertile offspring together is called a(n)
|
[
"species"
] |
5561767dc0fb4b53a604861f031a85a5
|
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Humans did not reach space until the second half of the 20th century. They needed somehow to break past Earths gravity. A rocket moves rapidly in one direction. The device is propelled by particles flying out of it at high speed in the other direction. There are records of the Chinese using rockets in war against the Mongols as early as the 13th century. The Mongols then used rockets to attack Eastern Europe. Early rockets were also used to launch fireworks. Rockets were used for centuries before anyone could explain how they worked. The theory came about in 1687. Isaac Newton (16431727) described three basic laws of motion, now referred to as Newtons Laws of Motion: 1. An object in motion will remain in motion unless acted upon by a force. 2. Force equals mass multiplied by acceleration. 3. To every action, there is an equal and opposite reaction. Which of these three best explains how a rocket works? Newtons third law of motion. When a rockets propulsion pushes in one direction, the rocket moves in the opposite direction, as seen in the Figure 23.12. For a long time, many people believed that a rocket wouldnt work in space. There would be nothing for the rocket to push against. But they do work! Fuel is ignited in a chamber. The gases in the chamber explode. The explosion creates pressure that forces the gases out of one side of the rocket. The rocket moves in the opposite direction, as shown in Figure 23.13. The force pushing the rocket is called thrust. For centuries, rockets were powered by gunpowder or other solid fuels. These rockets could travel only short distances. Around the turn of the 20th century, several breakthroughs took place. These breakthroughs led to rockets that could travel beyond Earth. Liquid fuel gave rockets enough power to escape Earths gravity (Figure 23.14). By using multiple stages, empty fuel containers could drop away. This reduced the mass of the rocket so that it could fly higher. Rockets were used during World War II. The V2 was the first human-made object to travel high enough to be considered in space (Figure 23.15). Its altitude was 176 km (109 miles) above Earths surface. Wernher von Braun was a German rocket scientist. After he fled Germany in WWII, he helped the United States develop missile weapons. After the war, von Braun worked for NASA. He designed the Saturn V rocket (Figure One of the first uses of rockets in space was to launch satellites. A satellite is an object that orbits a larger object. An orbit is a circular or elliptical path around an object. Natural objects in orbit are called natural satellites. The Moon is a natural satellite. Human-made objects in orbit are called artificial satellites. There are more and more artificial satellites orbiting Earth all the time. They all get into space using some sort of rocket. Why do satellites stay in orbit? Why dont they crash into Earth due to the planets gravity? Newtons law of universal gravitation describes what happens. Every object in the universe is attracted to every other object. Gravity makes an apple fall to the ground. Gravity also keeps you from floating away into the sky. Gravity holds the Moon in orbit around Earth. It keeps Earth in orbit around the Sun. Newton used an example to explain how gravity makes orbiting possible. Imagine a cannonball launched from a high mountain, as shown in Figure 23.17. If the cannonball is launched at a slow speed, it will fall back to Earth. This is shown as paths (A) and (B). Something different happens if the cannonball is launched at a fast speed. The Earth below curves away at the same rate that the cannonball falls. The cannonball then goes into a circular orbit, as in path (C). If the cannonball is launched even faster, it could go into an elliptical orbit (D). It might even leave Earths gravity and go into space (E). Unfortunately, Newtons idea would not work in real life. A cannonball launched at a fast speed from Mt. Everest would not go into orbit.
|
circular or elliptical path around an object
|
[
"orbit"
] |
c7f7eee15c434b4e943d0b64b737c952
|
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Humans did not reach space until the second half of the 20th century. They needed somehow to break past Earths gravity. A rocket moves rapidly in one direction. The device is propelled by particles flying out of it at high speed in the other direction. There are records of the Chinese using rockets in war against the Mongols as early as the 13th century. The Mongols then used rockets to attack Eastern Europe. Early rockets were also used to launch fireworks. Rockets were used for centuries before anyone could explain how they worked. The theory came about in 1687. Isaac Newton (16431727) described three basic laws of motion, now referred to as Newtons Laws of Motion: 1. An object in motion will remain in motion unless acted upon by a force. 2. Force equals mass multiplied by acceleration. 3. To every action, there is an equal and opposite reaction. Which of these three best explains how a rocket works? Newtons third law of motion. When a rockets propulsion pushes in one direction, the rocket moves in the opposite direction, as seen in the Figure 23.12. For a long time, many people believed that a rocket wouldnt work in space. There would be nothing for the rocket to push against. But they do work! Fuel is ignited in a chamber. The gases in the chamber explode. The explosion creates pressure that forces the gases out of one side of the rocket. The rocket moves in the opposite direction, as shown in Figure 23.13. The force pushing the rocket is called thrust. For centuries, rockets were powered by gunpowder or other solid fuels. These rockets could travel only short distances. Around the turn of the 20th century, several breakthroughs took place. These breakthroughs led to rockets that could travel beyond Earth. Liquid fuel gave rockets enough power to escape Earths gravity (Figure 23.14). By using multiple stages, empty fuel containers could drop away. This reduced the mass of the rocket so that it could fly higher. Rockets were used during World War II. The V2 was the first human-made object to travel high enough to be considered in space (Figure 23.15). Its altitude was 176 km (109 miles) above Earths surface. Wernher von Braun was a German rocket scientist. After he fled Germany in WWII, he helped the United States develop missile weapons. After the war, von Braun worked for NASA. He designed the Saturn V rocket (Figure One of the first uses of rockets in space was to launch satellites. A satellite is an object that orbits a larger object. An orbit is a circular or elliptical path around an object. Natural objects in orbit are called natural satellites. The Moon is a natural satellite. Human-made objects in orbit are called artificial satellites. There are more and more artificial satellites orbiting Earth all the time. They all get into space using some sort of rocket. Why do satellites stay in orbit? Why dont they crash into Earth due to the planets gravity? Newtons law of universal gravitation describes what happens. Every object in the universe is attracted to every other object. Gravity makes an apple fall to the ground. Gravity also keeps you from floating away into the sky. Gravity holds the Moon in orbit around Earth. It keeps Earth in orbit around the Sun. Newton used an example to explain how gravity makes orbiting possible. Imagine a cannonball launched from a high mountain, as shown in Figure 23.17. If the cannonball is launched at a slow speed, it will fall back to Earth. This is shown as paths (A) and (B). Something different happens if the cannonball is launched at a fast speed. The Earth below curves away at the same rate that the cannonball falls. The cannonball then goes into a circular orbit, as in path (C). If the cannonball is launched even faster, it could go into an elliptical orbit (D). It might even leave Earths gravity and go into space (E). Unfortunately, Newtons idea would not work in real life. A cannonball launched at a fast speed from Mt. Everest would not go into orbit.
|
object that orbits a larger object
|
[
"satellite"
] |
7e21a28c3d4045d6b7c77190f789c3a1
|
[
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"end": [
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}
] |
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