Changes in Ecosystems

5.9CPredict 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 white-tailed 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 white-tailed 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 They will become endangered or extinct.B They will migrate to warmer areas of China.C They will become carnivores.D 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 They will become endangered or extinct.B They will migrate to warmer areas of China.C They will become carnivores.D 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 More carbon dioxide is released into the atmosphere.B More carbon dioxide is stored in animals.C More carbon dioxide is released into the soil.D 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 More carbon dioxide is released into the atmosphere.B More carbon dioxide is stored in animals.C More carbon dioxide is released into the soil.D More carbon dioxide is stored in plants.