Changes in Ecosystems
5.9C
Predict the effects of changes in ecosystems
caused by living organisms including humans
such as the overpopulation of grazers or the
building of highways.
1. A wetland was drained to build a mall. Two years
later, there were no more toads in that area. Why did
the toads disappear?
A The toads were destroyed by the construction
equipment.
B The toads died because toads cannot breathe out of
water.
C The toads were frightened and went into the woods.
D The toads got their food from the wetland
ecosystem.
1. A wetland was drained to build a mall. Two years
later, there were no more toads in that area. Why did
the toads disappear?
A The toads were destroyed by the construction
equipment.
B The toads died because toads cannot breathe out of
water.
C The toads were frightened and went into the woods.
D The toads got their food from the wetland
ecosystem.
2. What might happen if the population of whitetailed deer decreases in size?
A White-tailed deer will have more food.
B The number of white-tailed deer the habitat
can support will decrease.
C The number of white-tailed deer will increase.
D Weaker white-tailed deer will survive longer.
2. What might happen if the population of whitetailed deer decreases in size?
A White-tailed deer will have more food.
B The number of white-tailed deer the habitat
can support will decrease.
C The number of white-tailed deer will increase.
D Weaker white-tailed deer will survive longer.
3. The Great Barrier Reef has a number of
endangered species which live only in that
ecosystem. What would MOST LIKELY happen if
pollution killed most of the coral that made up the
reef?
A The endangered species might become extinct.
B The animals on the reef would find a new habitat.
C The population size of the endangered species
would increase.
D The endangered species would take the niche of
the dead coral.
3. The Great Barrier Reef has a number of
endangered species which live only in that
ecosystem. What would MOST LIKELY happen if
pollution killed most of the coral that made up the
reef?
A The endangered species might become extinct.
B The animals on the reef would find a new habitat.
C The population size of the endangered species
would increase.
D The endangered species would take the niche of
the dead coral.
4. A species of giant pandas lives only in central
China. Bamboo, a tall, green tropical plant, is the
main food source for these animals. Large areas of
bamboo are being cut down in central China to
make room for growing other crops. What will
MOST LIKELY happen to these giant pandas?
A
B
C
D
They will become endangered or extinct.
They will migrate to warmer areas of China.
They will become carnivores.
They will begin to live in caves.
4. A species of giant pandas lives only in central
China. Bamboo, a tall, green tropical plant, is the
main food source for these animals. Large areas of
bamboo are being cut down in central China to
make room for growing other crops. What will
MOST LIKELY happen to these giant pandas?
A
B
C
D
They will become endangered or extinct.
They will migrate to warmer areas of China.
They will become carnivores.
They will begin to live in caves.
5. How does too much fishing in an area affect its
ecosystem?
A The fish will lay many more eggs to replace the
fish that were caught.
B Organisms that eat the fish could become
endangered due to starvation.
C Organisms that eat the fish will have to start
eating plants.
D People could eat too many fish and become ill.
5. How does too much fishing in an area affect its
ecosystem?
A The fish will lay many more eggs to replace the
fish that were caught.
B Organisms that eat the fish could become
endangered due to starvation.
C Organisms that eat the fish will have to start
eating plants.
D People could eat too many fish and become ill.
6. Tropical rainforests are cut down and burned at a very high
rate in many parts of the world. An area the size of a football
field is destroyed every second of every day. The burning
wood and vegetation release large amounts of carbon
dioxide. Fewer plants remain to take in carbon dioxide. How
does this burning affect the carbon cycle in tropical rain
forests?
A
B
C
D
More carbon dioxide is released into the atmosphere.
More carbon dioxide is stored in animals.
More carbon dioxide is released into the soil.
More carbon dioxide is stored in plants.
6. Tropical rainforests are cut down and burned at a very high
rate in many parts of the world. An area the size of a football
field is destroyed every second of every day. The burning
wood and vegetation release large amounts of carbon
dioxide. Fewer plants remain to take in carbon dioxide. How
does this burning affect the carbon cycle in tropical rain
forests?
A
B
C
D
More carbon dioxide is released into the atmosphere.
More carbon dioxide is stored in animals.
More carbon dioxide is released into the soil.
More carbon dioxide is stored in plants.