How do the activities of a keystone species affect the biodiversity of an ecosystem?

1.How do the activities of a keystone species affect the biodiversity of an ecosystem?

A.They increase biodiversity.
B.They decrease biodiversity.
C.They have no effect on biodiversity.
D.Biodiversity remains the same but the species change.
2.Which is a biotic factor in an earthworm's ecosystem?

A.soil
B.soil bacteria
C.moisture in soil
D.gravel
3.Which is a characteristic of an ecosystem in approximate equilibrium?

A.The kinds of organisms do not change.
B.Biotic factors do not change.
C.Abiotic factors do not change.
D.The total number of organisms do not change.
4.Which kind of ecosystem is most likely to have the largest amount of biodiversity?

A.desert
B.rain puddle
C.river
D.tropical rain forest
5.What is likely to occur in an ecosystem if all members of a keystone species die?

A.Another species will become the keystone species.
B.A keystone species from another ecosystem may take over.
C.Most species in the ecosystem will be severely affected.
D.The ecosystem will not change.
6.All photosynthetic organisms use carbon dioxide and water to make sugar and oxygen. Do all chemosynthetic organisms perform the same chemical reactions?

A.Yes, chemosynthesis makes sugar and hydrochloric acid from hydrogen sulfide.
B.Yes, all chemosynthetic organisms make sugar and sulfuric acid from hydrogen sulfide.
C.No, many chemosynthetic reactions occur, but all begin with hydrogen sulfide.
D.No, many chemosynthetic reactions occur, depending on the chemicals present.
7.What term describes a consumer?

A.heterotroph
B.autotroph
C.producer
D.chemosynthetic
8.What kind of organism provides the basis for an ecosystem's energy?

A.heterotroph
B.autotroph
C.consumer
D.scavenger
9.Where does most of the energy in an ecosystem originate?

A.food
B.sunlight
C.chemicals
D.organisms
10.What process do most producers use to obtain energy?

A.photosynthesis
B.glycolysis
C.chemosynthesis
D.fermentation