2Question 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.
3Answer…c. No animal or plant drives out other animals or plants.
4Question 2A meadow has too many rabbits. What would help balance this ecosystem?a. more rain that grass needsb. more foxes that eat rabbitsc. fewer foxes that eat rabbitsd. more grass for rabbits to eat
6Question 3How 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.
7c. Grass makes oxygen, and animals use it. Answer…c. Grass makes oxygen, and animals use it.
8Question 4 What impact does a parasite have in an ecosystem? a. helps the entire ecosystemb. hurts one organism and helps anotherc. helps both the host organism and parasited. hurts both the host organism and parasite
9b. hurts one organism and helps another Answer…b. hurts one organism and helps another
10Question 5How 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.
11c. The number of foxes would decrease. Answer…c. The number of foxes would decrease.
12Question 6 Which would cause an ecosystem to change quickly? a. an earthquakeb. a lake drying upc. a climate changed. a lake becoming a marsh
14Question 7What might be the effect on an ecosystem of a climate change from rainy to dry?a. no changeb. a change from plants to animalsc. a change from a forest to marshd. a change in kinds of plants and animals
15Answer…d. a change in kinds of plants and animals
16Question 8What 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.
22Question 11How 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.
23Answer…d. One hunts at night, and the other hunts during daytime.
24Question 12 Why did the United States establish national parks? a. to make money for the national governmentb. to provide Americans with great vacation spotsc. to preserve nature’s beauty and habitats of plants and animalsd. to give Americans a chance to see things they’ve never seen before.
25Answer…c. to preserve nature’s beauty and habitats of plants and animals
26Question 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.
27Answer…b. Mining companies can replace the soil.