1. As free oxygen increased in the early atmosphere, A) most anaerobic organisms

ID: 214200 • Letter: 1

Question

1. As free oxygen increased in the early atmosphere,

A) most anaerobic organisms perished.

B) anaerobic chemotrophs survived in seafloor

sediments.

C) some chemotrophs began to make their living

at hydrothermal vents on the

seafloor.

D) some anaerobic organisms survived in soil.

E) all of these happened.

2. Which of the following is false concerning

autotrophs?

A) They feed themselves and all heterotrophs.

B) They slow the rate of global warming.

C) They play a role in mineral recycling.

D) They are the basis for oceanic food chains.

E) Without them life on earth would still be

possible.

3. Which of the following would NOT be TRUE of

CAM plants?

A) They fix carbon only once.

B) They live in desert environments.

C) They fix carbon mostly during the day.

D) They open stomata only at night.

E) They grow slowly.

1-option e is correct because anaerobic organism not survive in environment ,some survive in soil.

2-option e is correct because without autotrophs, there is nothing to eat for heterotrophs.

3-option c is correct because cam plant fic carbon only at night. Stomata open during night.