1. Chapter 4 Review

2. Question 1 Which describes a balanced ecosystem?
a. There is enough food for people to exist.
b. One type of animal and plant depend on each other.
c. No animal or plant drives out other animals or plants.
d. Humans create shelter and food for animals and plants.

3. Answer…
c. No animal or plant drives out other animals or plants.

4. Question 2
A meadow has too many rabbits. What would help balance this ecosystem?
a. more rain that grass needs
b. more foxes that eat rabbits
c. fewer foxes that eat rabbits
d. more grass for rabbits to eat

5. Answer…
b. more foxes that eat rabbits

6. Question 3
How do grass and rabbits’ interactions help balance their ecosystem?
a. Rabbits make homes in grass.
b. Grass and rabbits both need oxygen.
c. Grass makes oxygen, and animals use it.
d. Grass depends on rabbits to protect it.

7. c. Grass makes oxygen, and animals use it.
Answer…
c. Grass makes oxygen, and animals use it.

8. Question 4 What impact does a parasite have in an ecosystem?
a. helps the entire ecosystem
b. hurts one organism and helps another
c. helps both the host organism and parasite
d. hurts both the host organism and parasite

9. b. hurts one organism and helps another
Answer…
b. hurts one organism and helps another

10. Question 5
How would an ecosystem change if the rabbits that were the main prey for foxes became sick and died?
a. The foxes would find new prey.
b. The number of foxes would increase.
c. The number of foxes would decrease.
d. The foxes and rabbits would compete for food.

11. c. The number of foxes would decrease.
Answer…
c. The number of foxes would decrease.

12. Question 6 Which would cause an ecosystem to change quickly?
a. an earthquake
b. a lake drying up
c. a climate change
d. a lake becoming a marsh

13. Answer…
a. an earthquake

14. Question 7
What might be the effect on an ecosystem of a climate change from rainy to dry?
a. no change
b. a change from plants to animals
c. a change from a forest to marsh
d. a change in kinds of plants and animals

15. Answer…
d. a change in kinds of plants and animals

16. Question 8
What could scientists tell from a fish fossil found in a desert?
a. That fish is now extinct.
b. Fish once had legs to travel.
c. Fish once lived in dry places.
d. The desert was once a sea or lake.

17. Answer…
d. The desert was once a sea or lake.

18. Question 9 What might be a reason an animal becomes extinct?
a. It is a predator.
b. It produces oxygen.
c. Its habitat is destroyed.
d. It adapts to its environment.

19. c. Its habitat is destroyed.
Answer…
c. Its habitat is destroyed.

20. Question 10
What is one way people can disturb the balance of ecosystems?
a. breathing air
b. planting trees
c. riding bicycles
d. building houses

21. Answer…
d. building houses

22. Question 11
How are a hawk and an owl able to succeed, even though they compete for food?
a. The hawk eats the owl.
b. The owl changes its diet.
c. One animal moves to a different habitat.
d. One hunts at night, and the other hunts during daytime.

23. Answer…
d. One hunts at night, and the other hunts during daytime.

24. Question 12 Why did the United States establish national parks?
a. to make money for the national government
b. to provide Americans with great vacation spots
c. to preserve nature’s beauty and habitats of plants and animals
d. to give Americans a chance to see things they’ve never seen before.

25. Answer…
c. to preserve nature’s beauty and habitats of plants and animals

26. Question 13 How can damage from strip mines be repaired?
a. Erosion can fill the hole.
b. Mining companies can replace the soil.
c. Rain can wash the rock away into rivers.
d. Mining companies can go mine in another place.

27. Answer…
b. Mining companies can replace the soil.