Unit 1 Lesson 7 Science

1. An event that changes an ecosystem for a long period of time is called:

• disturbance

• climate

• succession

2. The slow changes that take place in an ecosystem that has been disturbed is called:

• weathering

• succession

• disturbance

3. A natural change to an ecosystem occurs when

• a severe drought causes plants to die.

• trees are cut down to make paper.

• roads are built through a forest.

• a dam is constructed to hold back water.

4. What kinds of changes take place during succession?

• Animals move from one ecosystem to another.

• One or more species die out and no longer exist on Earth.

• Species slowly replace each other as the landscape changes.

• Plants stop growing and making food when days get shorter and colder.

5. After a forest fire, new plants and those that were not burned will ______ because the fire released nutrients into the soil.

6. Some animals hibernate during the winter because they

• lay eggs that need to be kept warm.

• need to avoid predators.

• change from one form to another.

• cannot find enough food.

7. Climate change can cause changes to ecosystems. What can happen to organisms that do not change with their ecosystems?

• They can disappear from Earth.

• They can stop the ecosystem from changing.

• They can form new ecosystems.

• They can be unaffected by the change.

8. _____________________ are the first to grow after a disturbance.

9. ____________ is when animals move in a cycle to fit their needs.

10. Changes to the climate cause

• plant cycles to change.

• animals to move to new areas

• disruption to food chains

• all of the above