The transition of the early earth's atmosphere from one rich in hydrogen to one rich in oxygen may be attributed to
A)photosystem II.
B)photosystem I.
C)the cyclic pathway of photosynthesis.
D)the light-independent reactions.
E)the activity of the electron transfer chain.

Question

Quizplus · Accepted Answer

Photosystem II played a crucial role in the transition of the early earth's atmosphere from one rich in hydrogen to one rich in oxygen through the process of oxygenic photosynthesis, which released oxygen as a byproduct.

The Transition of the Early Earth's Atmosphere from One Rich