Which of the following words means “Prolonged"?

Directions: Read the given passage and answer the following question.

Wetlands are areas where water covers the soil, or is present either at or near the surface of the soil all year or for varying periods of time during the year, including during the growing season. Water saturation (hydrology) largely determines how the soil develops and the types of plant and animal communities living in and on the soil. Wetlands may support both aquatic and terrestrial species. The prolonged presence of water creates conditions that favor the growth of specially adapted plants (hydrophytes) and promotes the development of characteristic wetland (hydric) soils. Wetlands vary widely because of regional and local differences in soils, topography, climate, hydrology, water chemistry, vegetation, and other factors, including human disturbance. Indeed, wetlands are found from the tundra to the tropics and on every continent except Antarctica. Two general categories of wetlands are recognized: coastal or tidal wetlands and inland or non-tidal wetlands. Tidal wetlands in the United States, are found along the Atlantic, Pacific, Alaskan, and Gulf coasts. They are closely linked to our nation's estuaries, where sea water mixes with fresh water to form an environment of varying salinities. The salt water and the fluctuating water levels (due to tidal action) combine to create a rather difficult environment for most plants. Consequently, many shallow coastal areas are unvegetated mud flats or sand flats. Some plants, however, have successfully adapted to this environment. Certain grasses and grasslike plants that adapt to the saline conditions form the tidal salt marshes that are found along the Atlantic, Gulf, and Pacific coasts. Mangrove swamps, with salt-loving shrubs or trees, are common in tropical climates, such as in southern Florida and Puerto Rico. Some tidal freshwater wetlands form beyond the upper edges of tidal salt marshes where the influence of salt water ends. Non-Tidal wetlands are most common on floodplains along rivers and streams (riparian wetlands), in isolated depressions surrounded by dry land (for example, playas, basins, and potholes), along the margins of lakes and ponds, and in other low-lying areas where the groundwater intercepts the soil surface or where precipitation sufficiently saturates the soil (vernal pools and bogs). Inland wetlands include marshes and wet meadows dominated by herbaceous plants, swamps dominated by shrubs, and wooded swamps dominated by trees. Many of these wetlands are seasonal (they are dry one or more seasons every year), and, particularly in the arid and semiarid West, may be wet only periodically. The quantity of water present and the timing of its presence in part determine the functions of a wetland and its role in the environment. Even wetlands that appear dry at times for significant parts of the year - such as vernal pools - often provide critical habitat for wildlife adapted to breeding exclusively in these areas.

What kinds of wetlands are found along the Gulf coasts?

Directions: Read the given passage and answer the following question.

Wetlands are areas where water covers the soil, or is present either at or near the surface of the soil all year or for varying periods of time during the year, including during the growing season. Water saturation (hydrology) largely determines how the soil develops and the types of plant and animal communities living in and on the soil. Wetlands may support both aquatic and terrestrial species. The prolonged presence of water creates conditions that favor the growth of specially adapted plants (hydrophytes) and promotes the development of characteristic wetland (hydric) soils. Wetlands vary widely because of regional and local differences in soils, topography, climate, hydrology, water chemistry, vegetation, and other factors, including human disturbance. Indeed, wetlands are found from the tundra to the tropics and on every continent except Antarctica. Two general categories of wetlands are recognized: coastal or tidal wetlands and inland or non-tidal wetlands. Tidal wetlands in the United States, are found along the Atlantic, Pacific, Alaskan, and Gulf coasts. They are closely linked to our nation's estuaries, where sea water mixes with fresh water to form an environment of varying salinities. The salt water and the fluctuating water levels (due to tidal action) combine to create a rather difficult environment for most plants. Consequently, many shallow coastal areas are unvegetated mud flats or sand flats. Some plants, however, have successfully adapted to this environment. Certain grasses and grasslike plants that adapt to the saline conditions form the tidal salt marshes that are found along the Atlantic, Gulf, and Pacific coasts. Mangrove swamps, with salt-loving shrubs or trees, are common in tropical climates, such as in southern Florida and Puerto Rico. Some tidal freshwater wetlands form beyond the upper edges of tidal salt marshes where the influence of salt water ends. Non-Tidal wetlands are most common on floodplains along rivers and streams (riparian wetlands), in isolated depressions surrounded by dry land (for example, playas, basins, and potholes), along the margins of lakes and ponds, and in other low-lying areas where the groundwater intercepts the soil surface or where precipitation sufficiently saturates the soil (vernal pools and bogs). Inland wetlands include marshes and wet meadows dominated by herbaceous plants, swamps dominated by shrubs, and wooded swamps dominated by trees. Many of these wetlands are seasonal (they are dry one or more seasons every year), and, particularly in the arid and semiarid West, may be wet only periodically. The quantity of water present and the timing of its presence in part determine the functions of a wetland and its role in the environment. Even wetlands that appear dry at times for significant parts of the year - such as vernal pools - often provide critical habitat for wildlife adapted to breeding exclusively in these areas.

Which of the following is the main characteristic of a vernal pool?

Directions: Read the given passage and answer the following question.

Wetlands are areas where water covers the soil, or is present either at or near the surface of the soil all year or for varying periods of time during the year, including during the growing season. Water saturation (hydrology) largely determines how the soil develops and the types of plant and animal communities living in and on the soil. Wetlands may support both aquatic and terrestrial species. The prolonged presence of water creates conditions that favor the growth of specially adapted plants (hydrophytes) and promotes the development of characteristic wetland (hydric) soils. Wetlands vary widely because of regional and local differences in soils, topography, climate, hydrology, water chemistry, vegetation, and other factors, including human disturbance. Indeed, wetlands are found from the tundra to the tropics and on every continent except Antarctica. Two general categories of wetlands are recognized: coastal or tidal wetlands and inland or non-tidal wetlands. Tidal wetlands in the United States, are found along the Atlantic, Pacific, Alaskan, and Gulf coasts. They are closely linked to our nation's estuaries, where sea water mixes with fresh water to form an environment of varying salinities. The salt water and the fluctuating water levels (due to tidal action) combine to create a rather difficult environment for most plants. Consequently, many shallow coastal areas are unvegetated mud flats or sand flats. Some plants, however, have successfully adapted to this environment. Certain grasses and grasslike plants that adapt to the saline conditions form the tidal salt marshes that are found along the Atlantic, Gulf, and Pacific coasts. Mangrove swamps, with salt-loving shrubs or trees, are common in tropical climates, such as in southern Florida and Puerto Rico. Some tidal freshwater wetlands form beyond the upper edges of tidal salt marshes where the influence of salt water ends. Non-Tidal wetlands are most common on floodplains along rivers and streams (riparian wetlands), in isolated depressions surrounded by dry land (for example, playas, basins, and potholes), along the margins of lakes and ponds, and in other low-lying areas where the groundwater intercepts the soil surface or where precipitation sufficiently saturates the soil (vernal pools and bogs). Inland wetlands include marshes and wet meadows dominated by herbaceous plants, swamps dominated by shrubs, and wooded swamps dominated by trees. Many of these wetlands are seasonal (they are dry one or more seasons every year), and, particularly in the arid and semiarid West, may be wet only periodically. The quantity of water present and the timing of its presence in part determine the functions of a wetland and its role in the environment. Even wetlands that appear dry at times for significant parts of the year - such as vernal pools - often provide critical habitat for wildlife adapted to breeding exclusively in these areas.

What kind of species do wetlands support?

Directions: Read the given passage and answer the following question.

Wetlands are areas where water covers the soil, or is present either at or near the surface of the soil all year or for varying periods of time during the year, including during the growing season. Water saturation (hydrology) largely determines how the soil develops and the types of plant and animal communities living in and on the soil. Wetlands may support both aquatic and terrestrial species. The prolonged presence of water creates conditions that favor the growth of specially adapted plants (hydrophytes) and promotes the development of characteristic wetland (hydric) soils. Wetlands vary widely because of regional and local differences in soils, topography, climate, hydrology, water chemistry, vegetation, and other factors, including human disturbance. Indeed, wetlands are found from the tundra to the tropics and on every continent except Antarctica. Two general categories of wetlands are recognized: coastal or tidal wetlands and inland or non-tidal wetlands. Tidal wetlands in the United States, are found along the Atlantic, Pacific, Alaskan, and Gulf coasts. They are closely linked to our nation's estuaries, where sea water mixes with fresh water to form an environment of varying salinities. The salt water and the fluctuating water levels (due to tidal action) combine to create a rather difficult environment for most plants. Consequently, many shallow coastal areas are unvegetated mud flats or sand flats. Some plants, however, have successfully adapted to this environment. Certain grasses and grasslike plants that adapt to the saline conditions form the tidal salt marshes that are found along the Atlantic, Gulf, and Pacific coasts. Mangrove swamps, with salt-loving shrubs or trees, are common in tropical climates, such as in southern Florida and Puerto Rico. Some tidal freshwater wetlands form beyond the upper edges of tidal salt marshes where the influence of salt water ends. Non-Tidal wetlands are most common on floodplains along rivers and streams (riparian wetlands), in isolated depressions surrounded by dry land (for example, playas, basins, and potholes), along the margins of lakes and ponds, and in other low-lying areas where the groundwater intercepts the soil surface or where precipitation sufficiently saturates the soil (vernal pools and bogs). Inland wetlands include marshes and wet meadows dominated by herbaceous plants, swamps dominated by shrubs, and wooded swamps dominated by trees. Many of these wetlands are seasonal (they are dry one or more seasons every year), and, particularly in the arid and semiarid West, may be wet only periodically. The quantity of water present and the timing of its presence in part determine the functions of a wetland and its role in the environment. Even wetlands that appear dry at times for significant parts of the year - such as vernal pools - often provide critical habitat for wildlife adapted to breeding exclusively in these areas.

Which of the following is not a reason for the wide variety in wetlands?

Directions: Read the given passage and answer the following question.

Wetlands are areas where water covers the soil, or is present either at or near the surface of the soil all year or for varying periods of time during the year, including during the growing season. Water saturation (hydrology) largely determines how the soil develops and the types of plant and animal communities living in and on the soil. Wetlands may support both aquatic and terrestrial species. The prolonged presence of water creates conditions that favor the growth of specially adapted plants (hydrophytes) and promotes the development of characteristic wetland (hydric) soils. Wetlands vary widely because of regional and local differences in soils, topography, climate, hydrology, water chemistry, vegetation, and other factors, including human disturbance. Indeed, wetlands are found from the tundra to the tropics and on every continent except Antarctica. Two general categories of wetlands are recognized: coastal or tidal wetlands and inland or non-tidal wetlands. Tidal wetlands in the United States, are found along the Atlantic, Pacific, Alaskan, and Gulf coasts. They are closely linked to our nation's estuaries, where sea water mixes with fresh water to form an environment of varying salinities. The salt water and the fluctuating water levels (due to tidal action) combine to create a rather difficult environment for most plants. Consequently, many shallow coastal areas are unvegetated mud flats or sand flats. Some plants, however, have successfully adapted to this environment. Certain grasses and grasslike plants that adapt to the saline conditions form the tidal salt marshes that are found along the Atlantic, Gulf, and Pacific coasts. Mangrove swamps, with salt-loving shrubs or trees, are common in tropical climates, such as in southern Florida and Puerto Rico. Some tidal freshwater wetlands form beyond the upper edges of tidal salt marshes where the influence of salt water ends. Non-Tidal wetlands are most common on floodplains along rivers and streams (riparian wetlands), in isolated depressions surrounded by dry land (for example, playas, basins, and potholes), along the margins of lakes and ponds, and in other low-lying areas where the groundwater intercepts the soil surface or where precipitation sufficiently saturates the soil (vernal pools and bogs). Inland wetlands include marshes and wet meadows dominated by herbaceous plants, swamps dominated by shrubs, and wooded swamps dominated by trees. Many of these wetlands are seasonal (they are dry one or more seasons every year), and, particularly in the arid and semiarid West, may be wet only periodically. The quantity of water present and the timing of its presence in part determine the functions of a wetland and its role in the environment. Even wetlands that appear dry at times for significant parts of the year - such as vernal pools - often provide critical habitat for wildlife adapted to breeding exclusively in these areas.

Which of the following most nearly means “Efficient”?

Directions: Read the given passage and answer the following question.

Xylem and Phloem. The Xylem is responsible for transporting water and certain nutrients from the root to the rest of the plant. The Phloem carries soluble organic material, i.e. food for the plant, which is produced in the leaves by photosynthesis to the other parts of the plant. The Xylem and phloem are the two types of vascular tissues that are present in plants. They are responsible for transporting water, minerals, food and other organic materials between the roots, stems and leaves of the plant. The Xylem and phloem form vascular bundles with each other, which means that together they are responsible for the efficient transportation of food, nutrients, minerals, and water in the plant, and hence the survival of the plant. Xylem is a type of transport tissue in vascular plants that is responsible for transporting water and certain nutrients from the root to the rest of the plant. Thus, it essentially flows in one direction, that is, from the bottom up to the sky towards the top of the plant. Its main function is to effectively transport water and nutrients from the soil to the various parts of the plant. The word ‘xylem’ is derived from the Greek word ‘xylon’, meaning wood. This is because wood is the best-known xylem tissue which is found throughout the tree. Xylem is a mixture of dead and living tissues, which are non-living at the time of maturity. It is made up of tracheids, vessels, xylem parenchyma, xylem fibres and ray parenchyma. Xylem cells are hard walled cells, which are stacked on top of each other and are mainly found in the center of the stem. Hence, xylem has another function, which is to provide mechanical support to the plant. The Xylem is surrounded by the phloem. The Phloem is the other type of transport tissue in vascular plants. Its main function is to carry soluble organic material, i.e. food for the plant, which is produced in the leaves by photosynthesis to the other parts of the plant. This process is called translocation. To do this effectively it flows both up and down the stem, unlike the xylem, which only flows up. The word ‘phloem’ is derived from the Greek word ‘phloos’, which means bark, as the phloem is the innermost layer of the bark in most trees. The Phloem is made up of sieve cells, sieve tube elements, phloem parenchyma, phloem fibres, and phloem ray cells. It consists of both living and dead soft-walled cells, where the outer phloem is made up of dead cells and the inner phloem is made of living cells.

Xylem and Phloem are responsible for which function in plants?

Directions: Read the given passage and answer the following question.

Xylem and Phloem. The Xylem is responsible for transporting water and certain nutrients from the root to the rest of the plant. The Phloem carries soluble organic material, i.e. food for the plant, which is produced in the leaves by photosynthesis to the other parts of the plant. The Xylem and phloem are the two types of vascular tissues that are present in plants. They are responsible for transporting water, minerals, food and other organic materials between the roots, stems and leaves of the plant. The Xylem and phloem form vascular bundles with each other, which means that together they are responsible for the efficient transportation of food, nutrients, minerals, and water in the plant, and hence the survival of the plant. Xylem is a type of transport tissue in vascular plants that is responsible for transporting water and certain nutrients from the root to the rest of the plant. Thus, it essentially flows in one direction, that is, from the bottom up to the sky towards the top of the plant. Its main function is to effectively transport water and nutrients from the soil to the various parts of the plant. The word ‘xylem’ is derived from the Greek word ‘xylon’, meaning wood. This is because wood is the best-known xylem tissue which is found throughout the tree. Xylem is a mixture of dead and living tissues, which are non-living at the time of maturity. It is made up of tracheids, vessels, xylem parenchyma, xylem fibres and ray parenchyma. Xylem cells are hard walled cells, which are stacked on top of each other and are mainly found in the center of the stem. Hence, xylem has another function, which is to provide mechanical support to the plant. The Xylem is surrounded by the phloem. The Phloem is the other type of transport tissue in vascular plants. Its main function is to carry soluble organic material, i.e. food for the plant, which is produced in the leaves by photosynthesis to the other parts of the plant. This process is called translocation. To do this effectively it flows both up and down the stem, unlike the xylem, which only flows up. The word ‘phloem’ is derived from the Greek word ‘phloos’, which means bark, as the phloem is the innermost layer of the bark in most trees. The Phloem is made up of sieve cells, sieve tube elements, phloem parenchyma, phloem fibres, and phloem ray cells. It consists of both living and dead soft-walled cells, where the outer phloem is made up of dead cells and the inner phloem is made of living cells.

Phloem is made of which of the following?

Directions: Read the given passage and answer the following question.

Xylem and Phloem. The Xylem is responsible for transporting water and certain nutrients from the root to the rest of the plant. The Phloem carries soluble organic material, i.e. food for the plant, which is produced in the leaves by photosynthesis to the other parts of the plant. The Xylem and phloem are the two types of vascular tissues that are present in plants. They are responsible for transporting water, minerals, food and other organic materials between the roots, stems and leaves of the plant. The Xylem and phloem form vascular bundles with each other, which means that together they are responsible for the efficient transportation of food, nutrients, minerals, and water in the plant, and hence the survival of the plant. Xylem is a type of transport tissue in vascular plants that is responsible for transporting water and certain nutrients from the root to the rest of the plant. Thus, it essentially flows in one direction, that is, from the bottom up to the sky towards the top of the plant. Its main function is to effectively transport water and nutrients from the soil to the various parts of the plant. The word ‘xylem’ is derived from the Greek word ‘xylon’, meaning wood. This is because wood is the best-known xylem tissue which is found throughout the tree. Xylem is a mixture of dead and living tissues, which are non-living at the time of maturity. It is made up of tracheids, vessels, xylem parenchyma, xylem fibres and ray parenchyma. Xylem cells are hard walled cells, which are stacked on top of each other and are mainly found in the center of the stem. Hence, xylem has another function, which is to provide mechanical support to the plant. The Xylem is surrounded by the phloem. The Phloem is the other type of transport tissue in vascular plants. Its main function is to carry soluble organic material, i.e. food for the plant, which is produced in the leaves by photosynthesis to the other parts of the plant. This process is called translocation. To do this effectively it flows both up and down the stem, unlike the xylem, which only flows up. The word ‘phloem’ is derived from the Greek word ‘phloos’, which means bark, as the phloem is the innermost layer of the bark in most trees. The Phloem is made up of sieve cells, sieve tube elements, phloem parenchyma, phloem fibres, and phloem ray cells. It consists of both living and dead soft-walled cells, where the outer phloem is made up of dead cells and the inner phloem is made of living cells.

In which direction does Xylem transport nutrients to plants?

Directions: Read the given passage and answer the following question.

Xylem and Phloem. The Xylem is responsible for transporting water and certain nutrients from the root to the rest of the plant. The Phloem carries soluble organic material, i.e. food for the plant, which is produced in the leaves by photosynthesis to the other parts of the plant. The Xylem and phloem are the two types of vascular tissues that are present in plants. They are responsible for transporting water, minerals, food and other organic materials between the roots, stems and leaves of the plant. The Xylem and phloem form vascular bundles with each other, which means that together they are responsible for the efficient transportation of food, nutrients, minerals, and water in the plant, and hence the survival of the plant. Xylem is a type of transport tissue in vascular plants that is responsible for transporting water and certain nutrients from the root to the rest of the plant. Thus, it essentially flows in one direction, that is, from the bottom up to the sky towards the top of the plant. Its main function is to effectively transport water and nutrients from the soil to the various parts of the plant. The word ‘xylem’ is derived from the Greek word ‘xylon’, meaning wood. This is because wood is the best-known xylem tissue which is found throughout the tree. Xylem is a mixture of dead and living tissues, which are non-living at the time of maturity. It is made up of tracheids, vessels, xylem parenchyma, xylem fibres and ray parenchyma. Xylem cells are hard walled cells, which are stacked on top of each other and are mainly found in the center of the stem. Hence, xylem has another function, which is to provide mechanical support to the plant. The Xylem is surrounded by the phloem. The Phloem is the other type of transport tissue in vascular plants. Its main function is to carry soluble organic material, i.e. food for the plant, which is produced in the leaves by photosynthesis to the other parts of the plant. This process is called translocation. To do this effectively it flows both up and down the stem, unlike the xylem, which only flows up. The word ‘phloem’ is derived from the Greek word ‘phloos’, which means bark, as the phloem is the innermost layer of the bark in most trees. The Phloem is made up of sieve cells, sieve tube elements, phloem parenchyma, phloem fibres, and phloem ray cells. It consists of both living and dead soft-walled cells, where the outer phloem is made up of dead cells and the inner phloem is made of living cells.

Which of the following helps in moving molecules fast?

Directions: Read the given passage and answer the following question.

Active and passive transport: While active transport requires energy and work, passive transport does not. There are several different types of this easy movement of molecules. It could be as simple as molecules moving freely such as osmosis or diffusion. There may also be proteins in the cell membrane that act as channels to help the movement along. And of course there is an in-between transport process where very small molecules are able to cross a semi-permeable membrane. Sometimes, proteins are used to help move molecules more quickly. It is a process called facilitated diffusion. It could be as simple as bringing in a glucose molecule. Since the cell membrane will not allow glucose to cross by diffusion, helpers are needed. The cell might notice outside fluids rushing by with free glucose molecules. The membrane proteins then grab one molecule and shift their position to bring the molecule into the cell. That's an easy situation of passive transport because the glucose is moving from higher to lower concentration. It's moving down a concentration gradient. If you needed to remove glucose, the cell would require energy. Sometimes cells are in an area where there is a large concentration difference. For example, oxygen molecule concentrations could be very high outside of the cell and very low inside. Those oxygen molecules are so small that they are able to cross the lipid bilayer and enter the cell. There is no energy needed for this process. In this case, it's good for the cell because cells need oxygen to survive. It can also happen with other molecules that can kill a cell. Another big example of passive transport is osmosis. This is a water specific process. Usually, cells are in an environment where there is one concentration of ions outside and one inside. Because concentrations like to be the same, the cell can pump ions in an out to stay alive. Osmosis is the movement of water across the membrane. For a cell to survive, ion concentrations need to be the same on both sides of the cell membrane. If the cell does not pump out all of its extra ions to even out the concentrations, the water is going to move in. This can be very bad. The cell can swell up and explode. The classic example of this type of swelling happens when red blood cells are placed in water. The water rushes in to the cells, they expand and eventually rupture.

Which is an important condition for a cell to be alive?

Directions: Read the given passage and answer the following question.

Active and passive transport: While active transport requires energy and work, passive transport does not. There are several different types of this easy movement of molecules. It could be as simple as molecules moving freely such as osmosis or diffusion. There may also be proteins in the cell membrane that act as channels to help the movement along. And of course there is an in-between transport process where very small molecules are able to cross a semi-permeable membrane. Sometimes, proteins are used to help move molecules more quickly. It is a process called facilitated diffusion. It could be as simple as bringing in a glucose molecule. Since the cell membrane will not allow glucose to cross by diffusion, helpers are needed. The cell might notice outside fluids rushing by with free glucose molecules. The membrane proteins then grab one molecule and shift their position to bring the molecule into the cell. That's an easy situation of passive transport because the glucose is moving from higher to lower concentration. It's moving down a concentration gradient. If you needed to remove glucose, the cell would require energy. Sometimes cells are in an area where there is a large concentration difference. For example, oxygen molecule concentrations could be very high outside of the cell and very low inside. Those oxygen molecules are so small that they are able to cross the lipid bilayer and enter the cell. There is no energy needed for this process. In this case, it's good for the cell because cells need oxygen to survive. It can also happen with other molecules that can kill a cell. Another big example of passive transport is osmosis. This is a water specific process. Usually, cells are in an environment where there is one concentration of ions outside and one inside. Because concentrations like to be the same, the cell can pump ions in an out to stay alive. Osmosis is the movement of water across the membrane. For a cell to survive, ion concentrations need to be the same on both sides of the cell membrane. If the cell does not pump out all of its extra ions to even out the concentrations, the water is going to move in. This can be very bad. The cell can swell up and explode. The classic example of this type of swelling happens when red blood cells are placed in water. The water rushes in to the cells, they expand and eventually rupture.

Which of the following is an easy way of passive transport?

Directions: Read the given passage and answer the following question.

Active and passive transport: While active transport requires energy and work, passive transport does not. There are several different types of this easy movement of molecules. It could be as simple as molecules moving freely such as osmosis or diffusion. There may also be proteins in the cell membrane that act as channels to help the movement along. And of course there is an in-between transport process where very small molecules are able to cross a semi-permeable membrane. Sometimes, proteins are used to help move molecules more quickly. It is a process called facilitated diffusion. It could be as simple as bringing in a glucose molecule. Since the cell membrane will not allow glucose to cross by diffusion, helpers are needed. The cell might notice outside fluids rushing by with free glucose molecules. The membrane proteins then grab one molecule and shift their position to bring the molecule into the cell. That's an easy situation of passive transport because the glucose is moving from higher to lower concentration. It's moving down a concentration gradient. If you needed to remove glucose, the cell would require energy. Sometimes cells are in an area where there is a large concentration difference. For example, oxygen molecule concentrations could be very high outside of the cell and very low inside. Those oxygen molecules are so small that they are able to cross the lipid bilayer and enter the cell. There is no energy needed for this process. In this case, it's good for the cell because cells need oxygen to survive. It can also happen with other molecules that can kill a cell. Another big example of passive transport is osmosis. This is a water specific process. Usually, cells are in an environment where there is one concentration of ions outside and one inside. Because concentrations like to be the same, the cell can pump ions in an out to stay alive. Osmosis is the movement of water across the membrane. For a cell to survive, ion concentrations need to be the same on both sides of the cell membrane. If the cell does not pump out all of its extra ions to even out the concentrations, the water is going to move in. This can be very bad. The cell can swell up and explode. The classic example of this type of swelling happens when red blood cells are placed in water. The water rushes in to the cells, they expand and eventually rupture.

What happens to red blood cells when they are placed in water?

Directions: Read the given passage and answer the following question.

Active and passive transport: While active transport requires energy and work, passive transport does not. There are several different types of this easy movement of molecules. It could be as simple as molecules moving freely such as osmosis or diffusion. There may also be proteins in the cell membrane that act as channels to help the movement along. And of course there is an in-between transport process where very small molecules are able to cross a semi-permeable membrane. Sometimes, proteins are used to help move molecules more quickly. It is a process called facilitated diffusion. It could be as simple as bringing in a glucose molecule. Since the cell membrane will not allow glucose to cross by diffusion, helpers are needed. The cell might notice outside fluids rushing by with free glucose molecules. The membrane proteins then grab one molecule and shift their position to bring the molecule into the cell. That's an easy situation of passive transport because the glucose is moving from higher to lower concentration. It's moving down a concentration gradient. If you needed to remove glucose, the cell would require energy. Sometimes cells are in an area where there is a large concentration difference. For example, oxygen molecule concentrations could be very high outside of the cell and very low inside. Those oxygen molecules are so small that they are able to cross the lipid bilayer and enter the cell. There is no energy needed for this process. In this case, it's good for the cell because cells need oxygen to survive. It can also happen with other molecules that can kill a cell. Another big example of passive transport is osmosis. This is a water specific process. Usually, cells are in an environment where there is one concentration of ions outside and one inside. Because concentrations like to be the same, the cell can pump ions in an out to stay alive. Osmosis is the movement of water across the membrane. For a cell to survive, ion concentrations need to be the same on both sides of the cell membrane. If the cell does not pump out all of its extra ions to even out the concentrations, the water is going to move in. This can be very bad. The cell can swell up and explode. The classic example of this type of swelling happens when red blood cells are placed in water. The water rushes in to the cells, they expand and eventually rupture.

Which of the following most nearly means “Diffusion”?

Directions: Read the given passage and answer the following question.

Active and passive transport: While active transport requires energy and work, passive transport does not. There are several different types of this easy movement of molecules. It could be as simple as molecules moving freely such as osmosis or diffusion. There may also be proteins in the cell membrane that act as channels to help the movement along. And of course there is an in-between transport process where very small molecules are able to cross a semi-permeable membrane. Sometimes, proteins are used to help move molecules more quickly. It is a process called facilitated diffusion. It could be as simple as bringing in a glucose molecule. Since the cell membrane will not allow glucose to cross by diffusion, helpers are needed. The cell might notice outside fluids rushing by with free glucose molecules. The membrane proteins then grab one molecule and shift their position to bring the molecule into the cell. That's an easy situation of passive transport because the glucose is moving from higher to lower concentration. It's moving down a concentration gradient. If you needed to remove glucose, the cell would require energy. Sometimes cells are in an area where there is a large concentration difference. For example, oxygen molecule concentrations could be very high outside of the cell and very low inside. Those oxygen molecules are so small that they are able to cross the lipid bilayer and enter the cell. There is no energy needed for this process. In this case, it's good for the cell because cells need oxygen to survive. It can also happen with other molecules that can kill a cell. Another big example of passive transport is osmosis. This is a water specific process. Usually, cells are in an environment where there is one concentration of ions outside and one inside. Because concentrations like to be the same, the cell can pump ions in an out to stay alive. Osmosis is the movement of water across the membrane. For a cell to survive, ion concentrations need to be the same on both sides of the cell membrane. If the cell does not pump out all of its extra ions to even out the concentrations, the water is going to move in. This can be very bad. The cell can swell up and explode. The classic example of this type of swelling happens when red blood cells are placed in water. The water rushes in to the cells, they expand and eventually rupture.

What do we call the process of transportation of water and nutrients in plants?

Directions: Read the given passage and answer the following question.

Xylem and Phloem. The Xylem is responsible for transporting water and certain nutrients from the root to the rest of the plant. The Phloem carries soluble organic material, i.e. food for the plant, which is produced in the leaves by photosynthesis to the other parts of the plant. The Xylem and phloem are the two types of vascular tissues that are present in plants. They are responsible for transporting water, minerals, food and other organic materials between the roots, stems and leaves of the plant. The Xylem and phloem form vascular bundles with each other, which means that together they are responsible for the efficient transportation of food, nutrients, minerals, and water in the plant, and hence the survival of the plant. Xylem is a type of transport tissue in vascular plants that is responsible for transporting water and certain nutrients from the root to the rest of the plant. Thus, it essentially flows in one direction, that is, from the bottom up to the sky towards the top of the plant. Its main function is to effectively transport water and nutrients from the soil to the various parts of the plant. The word ‘xylem’ is derived from the Greek word ‘xylon’, meaning wood. This is because wood is the best-known xylem tissue which is found throughout the tree. Xylem is a mixture of dead and living tissues, which are non-living at the time of maturity. It is made up of tracheids, vessels, xylem parenchyma, xylem fibres and ray parenchyma. Xylem cells are hard walled cells, which are stacked on top of each other and are mainly found in the center of the stem. Hence, xylem has another function, which is to provide mechanical support to the plant. The Xylem is surrounded by the phloem. The Phloem is the other type of transport tissue in vascular plants. Its main function is to carry soluble organic material, i.e. food for the plant, which is produced in the leaves by photosynthesis to the other parts of the plant. This process is called translocation. To do this effectively it flows both up and down the stem, unlike the xylem, which only flows up. The word ‘phloem’ is derived from the Greek word ‘phloos’, which means bark, as the phloem is the innermost layer of the bark in most trees. The Phloem is made up of sieve cells, sieve tube elements, phloem parenchyma, phloem fibres, and phloem ray cells. It consists of both living and dead soft-walled cells, where the outer phloem is made up of dead cells and the inner phloem is made of living cells.