RFVF4 [Reading] Final Exam

Flatfish

1- At first glance, flatfish might seem to be an awkward anomaly of evolution, because of one distinctive feature present in virtually no other living organism: the presence of both eyes on one side of the head. Nevertheless, this asymmetrical feature is of great benefit to flatfish, the majority of whom spend their lives on the bottom of the ocean floor. At birth, the eyes start out in the common symmetrical position of one eye on each side of the head; as the fish develops, one eye migrates to the left or right side of the head, depending on which side the fish faces toward the surface and away from the sandy ocean bed.

2- Members of the flatfish family, sand dabs and flounders, have an additional evolutionary advantage over many colorfully decorated ocean neighbors in that they are able to adapt their body coloration to different environments. These aquatic chameleons have flattened bodies that are well-suited to life along the ocean floor in the shallower areas of the continental shelf that they inhabit. They also have remarkably sensitive color vision that registers the subtlest gradations on the sea bottom and in the sea life around them. Information about the coloration of the environment is carried through the nervous system to chromatophores, which are pigment-carrying skin cells on the upper side of the fish. These chromatophores are able to accurately reproduce not only the colors but also the texture of the ocean floor. Each time that a sand dab or flounder finds itself in a new environment, the pattern on the body of the fish visible to potential predators adapts to fit in with the color and texture around it. However, the underside of a flatfish is generally pale or colorless.

3- Not all flatfish live exclusively along the bottom of the sea floor; some flatfish hunt for prey in the mid-levels of the ocean in which they dwell, with some types of flatfish breaking the surface of the water in pursuit of food. These flatfish that travel to higher levels in the water may not show the extremes of asymmetry that those that reside solely on the floor display. For example, while flounders, which occasionally hunt at mid-ocean level, have well-developed teeth on both sides of the jaw, their relatives, the soles, live almost exclusively at the bottom of the ocean, feed primarily on boneless prey and tend to have teeth on only one side of the jaw.

4- These oddly developed fish actually start out in similar fashion to other, commonly symmetrical fish. Flatfish spawn eggs that hatch into larvae and disperse away from the floor, floating throughout the water as plankton. During this initial stage of development the fish have protection in the form of spines covering the head, gills, and fins. As the fish mature into their adult form, one eye moves across the head to join with its counterpart; the protective spines drop away and the fish sinks to the bottom of the water, with its blind vulnerable side turned to the floor. Depending on the species and gender, flatfish may take several years to reach full maturity.

5- There are several types of flatfish that range in size and desirability for human consumption. One of the smallest types of flatfish is the Tarphops oligolepsis, with a span of just 1.8 inches (4.5 centimeters) and a weight of less than an ounce (2 grams). On the opposite end of the spectrum is the Atlantic halibut, which can reach a length of 8.2 feet (2.5 meters) and a weight of 700 pounds (316 kilograms). Fishermen hoping to reel in flatfish usually focus on the species that rise to mid-level or above from the bottom, as these present less of a challenge to catch. Thus, flounder and halibut are much more sought after, and caught, than sole. When sole are caught by fisherman, it is most likely in water only a few hundred feet deep, close to the edge of a reef or coastline.

Which is NOT mentioned in the passage regarding the eyes of flatfish?

• The symmetry of the eyes changes according to surface of the ocean bottom

• The eyes are originally formed on both sides of the head

• One eye moves to the other side as the fish mature

• The asymmetry helps the flatfish

Flatfish

1- At first glance, flatfish might seem to be an awkward anomaly of evolution, because of one distinctive feature present in virtually no other living organism: the presence of both eyes on one side of the head. Nevertheless, this asymmetrical feature is of great benefit to flatfish, the majority of whom spend their lives on the bottom of the ocean floor. At birth, the eyes start out in the common symmetrical position of one eye on each side of the head; as the fish develops, one eye migrates to the left or right side of the head, depending on which side the fish faces toward the surface and away from the sandy ocean bed.

2- Members of the flatfish family, sand dabs and flounders, have an additional evolutionary advantage over many colorfully decorated ocean neighbors in that they are able to adapt their body coloration to different environments. These aquatic chameleons have flattened bodies that are well-suited to life along the ocean floor in the shallower areas of the continental shelf that they inhabit. They also have remarkably sensitive color vision that registers the subtlest gradations on the sea bottom and in the sea life around them. Information about the coloration of the environment is carried through the nervous system to chromatophores, which are pigment-carrying skin cells on the upper side of the fish. These chromatophores are able to accurately reproduce not only the colors but also the texture of the ocean floor. Each time that a sand dab or flounder finds itself in a new environment, the pattern on the body of the fish visible to potential predators adapts to fit in with the color and texture around it. However, the underside of a flatfish is generally pale or colorless.

3- Not all flatfish live exclusively along the bottom of the sea floor; some flatfish hunt for prey in the mid-levels of the ocean in which they dwell, with some types of flatfish breaking the surface of the water in pursuit of food. These flatfish that travel to higher levels in the water may not show the extremes of asymmetry that those that reside solely on the floor display. For example, while flounders, which occasionally hunt at mid-ocean level, have well-developed teeth on both sides of the jaw, their relatives, the soles, live almost exclusively at the bottom of the ocean, feed primarily on boneless prey and tend to have teeth on only one side of the jaw.

4- These oddly developed fish actually start out in similar fashion to other, commonly symmetrical fish. Flatfish spawn eggs that hatch into larvae and disperse away from the floor, floating throughout the water as plankton. During this initial stage of development the fish have protection in the form of spines covering the head, gills, and fins. As the fish mature into their adult form, one eye moves across the head to join with its counterpart; the protective spines drop away and the fish sinks to the bottom of the water, with its blind vulnerable side turned to the floor. Depending on the species and gender, flatfish may take several years to reach full maturity.

5- There are several types of flatfish that range in size and desirability for human consumption. One of the smallest types of flatfish is the Tarphops oligolepsis, with a span of just 1.8 inches (4.5 centimeters) and a weight of less than an ounce (2 grams). On the opposite end of the spectrum is the Atlantic halibut, which can reach a length of 8.2 feet (2.5 meters) and a weight of 700 pounds (316 kilograms). Fishermen hoping to reel in flatfish usually focus on the species that rise to mid-level or above from the bottom, as these present less of a challenge to catch. Thus, flounder and halibut are much more sought after, and caught, than sole. When sole are caught by fisherman, it is most likely in water only a few hundred feet deep, close to the edge of a reef or coastline.

It is NOT stated in the passage that sand dabs

• Are a type of flatfish

• Are in the same family as flounders

• Are found in shallower water

• Are colorless all over their bodies

Flatfish

1- At first glance, flatfish might seem to be an awkward anomaly of evolution, because of one distinctive feature present in virtually no other living organism: the presence of both eyes on one side of the head. Nevertheless, this asymmetrical feature is of great benefit to flatfish, the majority of whom spend their lives on the bottom of the ocean floor. At birth, the eyes start out in the common symmetrical position of one eye on each side of the head; as the fish develops, one eye migrates to the left or right side of the head, depending on which side the fish faces toward the surface and away from the sandy ocean bed.

2- Members of the flatfish family, sand dabs and flounders, have an additional evolutionary advantage over many colorfully decorated ocean neighbors in that they are able to adapt their body coloration to different environments. These aquatic chameleons have flattened bodies that are well-suited to life along the ocean floor in the shallower areas of the continental shelf that they inhabit. They also have remarkably sensitive color vision that registers the subtlest gradations on the sea bottom and in the sea life around them. Information about the coloration of the environment is carried through the nervous system to chromatophores, which are pigment-carrying skin cells on the upper side of the fish. These chromatophores are able to accurately reproduce not only the colors but also the texture of the ocean floor. Each time that a sand dab or flounder finds itself in a new environment, the pattern on the body of the fish visible to potential predators adapts to fit in with the color and texture around it. However, the underside of a flatfish is generally pale or colorless.

3- Not all flatfish live exclusively along the bottom of the sea floor; some flatfish hunt for prey in the mid-levels of the ocean in which they dwell, with some types of flatfish breaking the surface of the water in pursuit of food. These flatfish that travel to higher levels in the water may not show the extremes of asymmetry that those that reside solely on the floor display. For example, while flounders, which occasionally hunt at mid-ocean level, have well-developed teeth on both sides of the jaw, their relatives, the soles, live almost exclusively at the bottom of the ocean, feed primarily on boneless prey and tend to have teeth on only one side of the jaw.

4- These oddly developed fish actually start out in similar fashion to other, commonly symmetrical fish. Flatfish spawn eggs that hatch into larvae and disperse away from the floor, floating throughout the water as plankton. During this initial stage of development the fish have protection in the form of spines covering the head, gills, and fins. As the fish mature into their adult form, one eye moves across the head to join with its counterpart; the protective spines drop away and the fish sinks to the bottom of the water, with its blind vulnerable side turned to the floor. Depending on the species and gender, flatfish may take several years to reach full maturity.

5- There are several types of flatfish that range in size and desirability for human consumption. One of the smallest types of flatfish is the Tarphops oligolepsis, with a span of just 1.8 inches (4.5 centimeters) and a weight of less than an ounce (2 grams). On the opposite end of the spectrum is the Atlantic halibut, which can reach a length of 8.2 feet (2.5 meters) and a weight of 700 pounds (316 kilograms). Fishermen hoping to reel in flatfish usually focus on the species that rise to mid-level or above from the bottom, as these present less of a challenge to catch. Thus, flounder and halibut are much more sought after, and caught, than sole. When sole are caught by fisherman, it is most likely in water only a few hundred feet deep, close to the edge of a reef or coastline.

All of the following are stated about the vision of sand dabs and flounders EXCEPT that they are

• Able to spot distance movements

• Able to see colors

• Able to see the sea bottom

• Able to distinguish other organisms

Flatfish

1- At first glance, flatfish might seem to be an awkward anomaly of evolution, because of one distinctive feature present in virtually no other living organism: the presence of both eyes on one side of the head. Nevertheless, this asymmetrical feature is of great benefit to flatfish, the majority of whom spend their lives on the bottom of the ocean floor. At birth, the eyes start out in the common symmetrical position of one eye on each side of the head; as the fish develops, one eye migrates to the left or right side of the head, depending on which side the fish faces toward the surface and away from the sandy ocean bed.

2- Members of the flatfish family, sand dabs and flounders, have an additional evolutionary advantage over many colorfully decorated ocean neighbors in that they are able to adapt their body coloration to different environments. These aquatic chameleons have flattened bodies that are well-suited to life along the ocean floor in the shallower areas of the continental shelf that they inhabit. They also have remarkably sensitive color vision that registers the subtlest gradations on the sea bottom and in the sea life around them. Information about the coloration of the environment is carried through the nervous system to chromatophores, which are pigment-carrying skin cells on the upper side of the fish. These chromatophores are able to accurately reproduce not only the colors but also the texture of the ocean floor. Each time that a sand dab or flounder finds itself in a new environment, the pattern on the body of the fish visible to potential predators adapts to fit in with the color and texture around it. However, the underside of a flatfish is generally pale or colorless.

3- Not all flatfish live exclusively along the bottom of the sea floor; some flatfish hunt for prey in the mid-levels of the ocean in which they dwell, with some types of flatfish breaking the surface of the water in pursuit of food. These flatfish that travel to higher levels in the water may not show the extremes of asymmetry that those that reside solely on the floor display. For example, while flounders, which occasionally hunt at mid-ocean level, have well-developed teeth on both sides of the jaw, their relatives, the soles, live almost exclusively at the bottom of the ocean, feed primarily on boneless prey and tend to have teeth on only one side of the jaw.

4- These oddly developed fish actually start out in similar fashion to other, commonly symmetrical fish. Flatfish spawn eggs that hatch into larvae and disperse away from the floor, floating throughout the water as plankton. During this initial stage of development the fish have protection in the form of spines covering the head, gills, and fins. As the fish mature into their adult form, one eye moves across the head to join with its counterpart; the protective spines drop away and the fish sinks to the bottom of the water, with its blind vulnerable side turned to the floor. Depending on the species and gender, flatfish may take several years to reach full maturity.

5- There are several types of flatfish that range in size and desirability for human consumption. One of the smallest types of flatfish is the Tarphops oligolepsis, with a span of just 1.8 inches (4.5 centimeters) and a weight of less than an ounce (2 grams). On the opposite end of the spectrum is the Atlantic halibut, which can reach a length of 8.2 feet (2.5 meters) and a weight of 700 pounds (316 kilograms). Fishermen hoping to reel in flatfish usually focus on the species that rise to mid-level or above from the bottom, as these present less of a challenge to catch. Thus, flounder and halibut are much more sought after, and caught, than sole. When sole are caught by fisherman, it is most likely in water only a few hundred feet deep, close to the edge of a reef or coastline.

It is NOT true that chromatophores

• Are skin cells

• Carry pigment

• Adapt to surrounding colors

• Change shape on the ocean floor

Flatfish

1- At first glance, flatfish might seem to be an awkward anomaly of evolution, because of one distinctive feature present in virtually no other living organism: the presence of both eyes on one side of the head. Nevertheless, this asymmetrical feature is of great benefit to flatfish, the majority of whom spend their lives on the bottom of the ocean floor. At birth, the eyes start out in the common symmetrical position of one eye on each side of the head; as the fish develops, one eye migrates to the left or right side of the head, depending on which side the fish faces toward the surface and away from the sandy ocean bed.

2- Members of the flatfish family, sand dabs and flounders, have an additional evolutionary advantage over many colorfully decorated ocean neighbors in that they are able to adapt their body coloration to different environments. These aquatic chameleons have flattened bodies that are well-suited to life along the ocean floor in the shallower areas of the continental shelf that they inhabit. They also have remarkably sensitive color vision that registers the subtlest gradations on the sea bottom and in the sea life around them. Information about the coloration of the environment is carried through the nervous system to chromatophores, which are pigment-carrying skin cells on the upper side of the fish. These chromatophores are able to accurately reproduce not only the colors but also the texture of the ocean floor. Each time that a sand dab or flounder finds itself in a new environment, the pattern on the body of the fish visible to potential predators adapts to fit in with the color and texture around it. However, the underside of a flatfish is generally pale or colorless.

3- Not all flatfish live exclusively along the bottom of the sea floor; some flatfish hunt for prey in the mid-levels of the ocean in which they dwell, with some types of flatfish breaking the surface of the water in pursuit of food. These flatfish that travel to higher levels in the water may not show the extremes of asymmetry that those that reside solely on the floor display. For example, while flounders, which occasionally hunt at mid-ocean level, have well-developed teeth on both sides of the jaw, their relatives, the soles, live almost exclusively at the bottom of the ocean, feed primarily on boneless prey and tend to have teeth on only one side of the jaw.

4- These oddly developed fish actually start out in similar fashion to other, commonly symmetrical fish. Flatfish spawn eggs that hatch into larvae and disperse away from the floor, floating throughout the water as plankton. During this initial stage of development the fish have protection in the form of spines covering the head, gills, and fins. As the fish mature into their adult form, one eye moves across the head to join with its counterpart; the protective spines drop away and the fish sinks to the bottom of the water, with its blind vulnerable side turned to the floor. Depending on the species and gender, flatfish may take several years to reach full maturity.

5- There are several types of flatfish that range in size and desirability for human consumption. One of the smallest types of flatfish is the Tarphops oligolepsis, with a span of just 1.8 inches (4.5 centimeters) and a weight of less than an ounce (2 grams). On the opposite end of the spectrum is the Atlantic halibut, which can reach a length of 8.2 feet (2.5 meters) and a weight of 700 pounds (316 kilograms). Fishermen hoping to reel in flatfish usually focus on the species that rise to mid-level or above from the bottom, as these present less of a challenge to catch. Thus, flounder and halibut are much more sought after, and caught, than sole. When sole are caught by fisherman, it is most likely in water only a few hundred feet deep, close to the edge of a reef or coastline.

The passage does NOT mention that

• Some flatfish do not live solely on the ocean floor

• All flatfish display the same level of asymmetry

• The asymmetry influences the teeth as well as the eyes of the flatfish

• Some flatfish may come above the surface of the water to hunt

Flatfish

1- At first glance, flatfish might seem to be an awkward anomaly of evolution, because of one distinctive feature present in virtually no other living organism: the presence of both eyes on one side of the head. Nevertheless, this asymmetrical feature is of great benefit to flatfish, the majority of whom spend their lives on the bottom of the ocean floor. At birth, the eyes start out in the common symmetrical position of one eye on each side of the head; as the fish develops, one eye migrates to the left or right side of the head, depending on which side the fish faces toward the surface and away from the sandy ocean bed.

2- Members of the flatfish family, sand dabs and flounders, have an additional evolutionary advantage over many colorfully decorated ocean neighbors in that they are able to adapt their body coloration to different environments. These aquatic chameleons have flattened bodies that are well-suited to life along the ocean floor in the shallower areas of the continental shelf that they inhabit. They also have remarkably sensitive color vision that registers the subtlest gradations on the sea bottom and in the sea life around them. Information about the coloration of the environment is carried through the nervous system to chromatophores, which are pigment-carrying skin cells on the upper side of the fish. These chromatophores are able to accurately reproduce not only the colors but also the texture of the ocean floor. Each time that a sand dab or flounder finds itself in a new environment, the pattern on the body of the fish visible to potential predators adapts to fit in with the color and texture around it. However, the underside of a flatfish is generally pale or colorless.

3- Not all flatfish live exclusively along the bottom of the sea floor; some flatfish hunt for prey in the mid-levels of the ocean in which they dwell, with some types of flatfish breaking the surface of the water in pursuit of food. These flatfish that travel to higher levels in the water may not show the extremes of asymmetry that those that reside solely on the floor display. For example, while flounders, which occasionally hunt at mid-ocean level, have well-developed teeth on both sides of the jaw, their relatives, the soles, live almost exclusively at the bottom of the ocean, feed primarily on boneless prey and tend to have teeth on only one side of the jaw.

4- These oddly developed fish actually start out in similar fashion to other, commonly symmetrical fish. Flatfish spawn eggs that hatch into larvae and disperse away from the floor, floating throughout the water as plankton. During this initial stage of development the fish have protection in the form of spines covering the head, gills, and fins. As the fish mature into their adult form, one eye moves across the head to join with its counterpart; the protective spines drop away and the fish sinks to the bottom of the water, with its blind vulnerable side turned to the floor. Depending on the species and gender, flatfish may take several years to reach full maturity.

5- There are several types of flatfish that range in size and desirability for human consumption. One of the smallest types of flatfish is the Tarphops oligolepsis, with a span of just 1.8 inches (4.5 centimeters) and a weight of less than an ounce (2 grams). On the opposite end of the spectrum is the Atlantic halibut, which can reach a length of 8.2 feet (2.5 meters) and a weight of 700 pounds (316 kilograms). Fishermen hoping to reel in flatfish usually focus on the species that rise to mid-level or above from the bottom, as these present less of a challenge to catch. Thus, flounder and halibut are much more sought after, and caught, than sole. When sole are caught by fisherman, it is most likely in water only a few hundred feet deep, close to the edge of a reef or coastline.

The passage mentions everything EXCEPT the following about the development of flatfish.

• Flatfish are initially spawned like other species of fish

• Flatfish lose their protective spines as they mature

• Flatfish grow to adulthood relatively quickly

• Flatfish fall to the ocean floor as they grow

Flatfish

1- At first glance, flatfish might seem to be an awkward anomaly of evolution, because of one distinctive feature present in virtually no other living organism: the presence of both eyes on one side of the head. Nevertheless, this asymmetrical feature is of great benefit to flatfish, the majority of whom spend their lives on the bottom of the ocean floor. At birth, the eyes start out in the common symmetrical position of one eye on each side of the head; as the fish develops, one eye migrates to the left or right side of the head, depending on which side the fish faces toward the surface and away from the sandy ocean bed.

2- Members of the flatfish family, sand dabs and flounders, have an additional evolutionary advantage over many colorfully decorated ocean neighbors in that they are able to adapt their body coloration to different environments. These aquatic chameleons have flattened bodies that are well-suited to life along the ocean floor in the shallower areas of the continental shelf that they inhabit. They also have remarkably sensitive color vision that registers the subtlest gradations on the sea bottom and in the sea life around them. Information about the coloration of the environment is carried through the nervous system to chromatophores, which are pigment-carrying skin cells on the upper side of the fish. These chromatophores are able to accurately reproduce not only the colors but also the texture of the ocean floor. Each time that a sand dab or flounder finds itself in a new environment, the pattern on the body of the fish visible to potential predators adapts to fit in with the color and texture around it. However, the underside of a flatfish is generally pale or colorless.

3- Not all flatfish live exclusively along the bottom of the sea floor; some flatfish hunt for prey in the mid-levels of the ocean in which they dwell, with some types of flatfish breaking the surface of the water in pursuit of food. These flatfish that travel to higher levels in the water may not show the extremes of asymmetry that those that reside solely on the floor display. For example, while flounders, which occasionally hunt at mid-ocean level, have well-developed teeth on both sides of the jaw, their relatives, the soles, live almost exclusively at the bottom of the ocean, feed primarily on boneless prey and tend to have teeth on only one side of the jaw.

4- These oddly developed fish actually start out in similar fashion to other, commonly symmetrical fish. Flatfish spawn eggs that hatch into larvae and disperse away from the floor, floating throughout the water as plankton. During this initial stage of development the fish have protection in the form of spines covering the head, gills, and fins. As the fish mature into their adult form, one eye moves across the head to join with its counterpart; the protective spines drop away and the fish sinks to the bottom of the water, with its blind vulnerable side turned to the floor. Depending on the species and gender, flatfish may take several years to reach full maturity.

5- There are several types of flatfish that range in size and desirability for human consumption. One of the smallest types of flatfish is the Tarphops oligolepsis, with a span of just 1.8 inches (4.5 centimeters) and a weight of less than an ounce (2 grams). On the opposite end of the spectrum is the Atlantic halibut, which can reach a length of 8.2 feet (2.5 meters) and a weight of 700 pounds (316 kilograms). Fishermen hoping to reel in flatfish usually focus on the species that rise to mid-level or above from the bottom, as these present less of a challenge to catch. Thus, flounder and halibut are much more sought after, and caught, than sole. When sole are caught by fisherman, it is most likely in water only a few hundred feet deep, close to the edge of a reef or coastline.

According to the passage, what is NOT true about the development of flatfish?

• They float in the water as plankton

• They are spawned away from the ocean floor

• They start out with spines to protect the head, fins, and gills

• The eyeless side faces the bottom of the ocean

Flatfish

1- At first glance, flatfish might seem to be an awkward anomaly of evolution, because of one distinctive feature present in virtually no other living organism: the presence of both eyes on one side of the head. Nevertheless, this asymmetrical feature is of great benefit to flatfish, the majority of whom spend their lives on the bottom of the ocean floor. At birth, the eyes start out in the common symmetrical position of one eye on each side of the head; as the fish develops, one eye migrates to the left or right side of the head, depending on which side the fish faces toward the surface and away from the sandy ocean bed.

2- Members of the flatfish family, sand dabs and flounders, have an additional evolutionary advantage over many colorfully decorated ocean neighbors in that they are able to adapt their body coloration to different environments. These aquatic chameleons have flattened bodies that are well-suited to life along the ocean floor in the shallower areas of the continental shelf that they inhabit. They also have remarkably sensitive color vision that registers the subtlest gradations on the sea bottom and in the sea life around them. Information about the coloration of the environment is carried through the nervous system to chromatophores, which are pigment-carrying skin cells on the upper side of the fish. These chromatophores are able to accurately reproduce not only the colors but also the texture of the ocean floor. Each time that a sand dab or flounder finds itself in a new environment, the pattern on the body of the fish visible to potential predators adapts to fit in with the color and texture around it. However, the underside of a flatfish is generally pale or colorless.

3- Not all flatfish live exclusively along the bottom of the sea floor; some flatfish hunt for prey in the mid-levels of the ocean in which they dwell, with some types of flatfish breaking the surface of the water in pursuit of food. These flatfish that travel to higher levels in the water may not show the extremes of asymmetry that those that reside solely on the floor display. For example, while flounders, which occasionally hunt at mid-ocean level, have well-developed teeth on both sides of the jaw, their relatives, the soles, live almost exclusively at the bottom of the ocean, feed primarily on boneless prey and tend to have teeth on only one side of the jaw.

4- These oddly developed fish actually start out in similar fashion to other, commonly symmetrical fish. Flatfish spawn eggs that hatch into larvae and disperse away from the floor, floating throughout the water as plankton. During this initial stage of development the fish have protection in the form of spines covering the head, gills, and fins. As the fish mature into their adult form, one eye moves across the head to join with its counterpart; the protective spines drop away and the fish sinks to the bottom of the water, with its blind vulnerable side turned to the floor. Depending on the species and gender, flatfish may take several years to reach full maturity.

5- There are several types of flatfish that range in size and desirability for human consumption. One of the smallest types of flatfish is the Tarphops oligolepsis, with a span of just 1.8 inches (4.5 centimeters) and a weight of less than an ounce (2 grams). On the opposite end of the spectrum is the Atlantic halibut, which can reach a length of 8.2 feet (2.5 meters) and a weight of 700 pounds (316 kilograms). Fishermen hoping to reel in flatfish usually focus on the species that rise to mid-level or above from the bottom, as these present less of a challenge to catch. Thus, flounder and halibut are much more sought after, and caught, than sole. When sole are caught by fisherman, it is most likely in water only a few hundred feet deep, close to the edge of a reef or coastline.

All of the following are true about flatfish EXCEPT

• Some flatfish are better for eating than others

• Flatfish vary greatly in size and weight

• The Atlantic halibut is a very large type of flatfish

• Sole is considered easier to catch than flounder or halibut

Limestone Caves

1- Caves, natural cavities formed within the earth, can be formed from varied substances, but the largest caves, measured by depth and length, are commonly created out of limestone. Limestone primarily derives from the hard outer shells of marine organisms, and was originally formed on ancient sea beds or at the bottom of oceans. Limestone caves are known as “solutional” caves since the limestone is dissolved, opening up a slowly expanding hole, which results in the creation of the cave. These caves can be spectacular structures filled with giant stalactites and stalagmites.

2- Limestone caves are formed in one of two ways. For a long time, it was accepted that all the caves were made by rainwater, a weak acid, when it dissolves calcite, or lime, out of limestone. Carbonic acid is formed when the rainwater combines with atmospheric carbon dioxide. Over time, the acid-laden water drips down into cracks, enlarging them into caves. However, more recently, it was revealed that some well-known caves, including the Carlsbad Caverns in New Mexico, were not formed by carbonic acid, but instead, by sulfuric acid. Apparently, microorganisms far beneath the earth’s surface consume oil and generate hydrogen sulfide. This hydrogen sulfide mixture rises to the earth’s surface and mixes with water, producing the sulfuric acid that eats away at the limestone. Thus, both methods involve water combining with another substance to form an acid that erodes the limestone, creating the caves.

3- Regardless of which type of acid initiates the erosion process, the liquid substances carry the dissolved limestone particles to other parts of the caves and deposit them. These deposits become “speleothems,” the structures that grow from the floors and ceilings, and cover the walls of the caves. These deposits can also form structures known as stalactites and stalagmites. All of the formations are created as the water evaporates on the surfaces of the cave, leaving behind the solid limestone grains that build up and create often unique and eye-catching shapes.

4- Stalactites, which extend down from cave ceilings, are formed in limestone caves when groundwater containing dissolved lime drips from the roof of the cave and leaves a thin deposit as it evaporates. Stalactites generally grow only a fraction of an inch each year, but over time a considerable number may grow to be several yards long. In cases where the supply of water is seasonal, they may actually have growth rings resembling those on tree trunks that indicate how old the stalactites are.

5- Stalagmites are formed on the floor of a limestone cave where water containing dissolved lime has dipped either from the cave ceiling or from a stalactite above. They develop in the same way as stalactites, when water containing dissolved limestone evaporates. The deposits of limestone gradually build up over hundreds or thousands of years. One of the tallest stalagmites, the Great Dome in Carlsbad Cavern, is over 67 feet (21 meters) high. Using currently accepted growth- rate calculations, it is estimated that the stalagmite reached this height in just under 4,000 years.

6- In some limestone caves with mature limestone development, stalactites and stalagmites grow together, creating limestone pillars that stretch from the cave floor to the cave ceiling. These pillars are referred to as “columns” due to their resemblance to the manmade structures used to support the roofs and ceilings of buildings. The growth rate of stalagmites and stalactites has proven difficult to measure with any consistency, making it hard to predict when the formations with the possibility of merging into columns might actually do so.

7- A fourth type of speleothem is called flowstone. Flowstone forms as the water flows or drips down the walls of the cave, leaving behind the limestone sediment. Flowstone, while having an irregular surface, develops much more smoothly and evenly than stalagmites and stalactites because of the large area that the water has to flow over.

8- In some caves, experts have determined that a lack of moisture will prevent further growth of the formation, while in others, rates of growth have varied depending on the amount of moisture and the speed of dripping or flowing water. While the growth rate of the cave formations is virtually imperceptible from one year to the next, an evaluation of thousands of years worth of data gives scientists the ability to estimate a yearly growth rate. In some caves, these estimators may take decades to confirm, and in others, they may never be validated since the dry conditions of those caves today hinder further growth of the structures.

Paragraph 1 states all of the following caves EXCEPT

• Most caves, of all sizes, are made of limestone

• Caves are measured by how deep and how long they are

• They are natural holes created in the earth

• They can be formed from different substances

Limestone Caves

1- Caves, natural cavities formed within the earth, can be formed from varied substances, but the largest caves, measured by depth and length, are commonly created out of limestone. Limestone primarily derives from the hard outer shells of marine organisms, and was originally formed on ancient sea beds or at the bottom of oceans. Limestone caves are known as “solutional” caves since the limestone is dissolved, opening up a slowly expanding hole, which results in the creation of the cave. These caves can be spectacular structures filled with giant stalactites and stalagmites.

2- Limestone caves are formed in one of two ways. For a long time, it was accepted that all the caves were made by rainwater, a weak acid, when it dissolves calcite, or lime, out of limestone. Carbonic acid is formed when the rainwater combines with atmospheric carbon dioxide. Over time, the acid-laden water drips down into cracks, enlarging them into caves. However, more recently, it was revealed that some well-known caves, including the Carlsbad Caverns in New Mexico, were not formed by carbonic acid, but instead, by sulfuric acid. Apparently, microorganisms far beneath the earth’s surface consume oil and generate hydrogen sulfide. This hydrogen sulfide mixture rises to the earth’s surface and mixes with water, producing the sulfuric acid that eats away at the limestone. Thus, both methods involve water combining with another substance to form an acid that erodes the limestone, creating the caves.

3- Regardless of which type of acid initiates the erosion process, the liquid substances carry the dissolved limestone particles to other parts of the caves and deposit them. These deposits become “speleothems,” the structures that grow from the floors and ceilings, and cover the walls of the caves. These deposits can also form structures known as stalactites and stalagmites. All of the formations are created as the water evaporates on the surfaces of the cave, leaving behind the solid limestone grains that build up and create often unique and eye-catching shapes.

4- Stalactites, which extend down from cave ceilings, are formed in limestone caves when groundwater containing dissolved lime drips from the roof of the cave and leaves a thin deposit as it evaporates. Stalactites generally grow only a fraction of an inch each year, but over time a considerable number may grow to be several yards long. In cases where the supply of water is seasonal, they may actually have growth rings resembling those on tree trunks that indicate how old the stalactites are.

5- Stalagmites are formed on the floor of a limestone cave where water containing dissolved lime has dipped either from the cave ceiling or from a stalactite above. They develop in the same way as stalactites, when water containing dissolved limestone evaporates. The deposits of limestone gradually build up over hundreds or thousands of years. One of the tallest stalagmites, the Great Dome in Carlsbad Cavern, is over 67 feet (21 meters) high. Using currently accepted growth- rate calculations, it is estimated that the stalagmite reached this height in just under 4,000 years.

6- In some limestone caves with mature limestone development, stalactites and stalagmites grow together, creating limestone pillars that stretch from the cave floor to the cave ceiling. These pillars are referred to as “columns” due to their resemblance to the manmade structures used to support the roofs and ceilings of buildings. The growth rate of stalagmites and stalactites has proven difficult to measure with any consistency, making it hard to predict when the formations with the possibility of merging into columns might actually do so.

7- A fourth type of speleothem is called flowstone. Flowstone forms as the water flows or drips down the walls of the cave, leaving behind the limestone sediment. Flowstone, while having an irregular surface, develops much more smoothly and evenly than stalagmites and stalactites because of the large area that the water has to flow over.

8- In some caves, experts have determined that a lack of moisture will prevent further growth of the formation, while in others, rates of growth have varied depending on the amount of moisture and the speed of dripping or flowing water. While the growth rate of the cave formations is virtually imperceptible from one year to the next, an evaluation of thousands of years worth of data gives scientists the ability to estimate a yearly growth rate. In some caves, these estimators may take decades to confirm, and in others, they may never be validated since the dry conditions of those caves today hinder further growth of the structures.

It is indicated in paragraph 2 that all of the following are part of the process of forming limestone caves EXCEPT that

• rainwater dissolves lime from limestone

• the acidic water seeps into breaks in the ground

• The lime in the water evaporates

• The cracks in the ground develop into caves