As free oxygen increased in the early atmosphere,
A)most anaerobic organisms perished.
B)some anaerobic organisms survived in seafloor sediments.
C)organisms evolved pathways for detoxifying oxygen.
D)the amount of UV radiation reaching the earth decreased.
E)all of these happened.

Question

Quizplus · Accepted Answer

As free oxygen increased in the early atmosphere, most anaerobic organisms perished, but some survived in seafloor sediments. Organisms also evolved pathways for detoxifying oxygen. Additionally, the amount of UV radiation reaching the earth decreased as the oxygen reacted with the ozone-forming molecules in the atmosphere. Therefore, all of these happened.

As Free Oxygen Increased in the Early Atmosphere