Oxygenic photosynthesis is made possible by the accumulation of oxygen in Earth's atmosphere and oceans. The primary producers of oxygen since 800 million years ago and those that power the modern carbon cycle are mostly:
A)cyanobacteria.
B)anoxygenic phototrophs.
C)algae and plants.
D)purple bacteria.

Question

Quizplus · Accepted Answer

Algae and plants are the primary producers of oxygen through oxygenic photosynthesis, which has been a major source of atmospheric oxygen for about the last 800 million years. Cyanobacteria played a crucial role earlier in Earth's history, but in the modern carbon cycle, algae and plants are predominant.

Oxygenic Photosynthesis Is Made Possible by the Accumulation of Oxygen