Increase in the population of photosynthetic bacteria using the oxygen-releasing pathway led to an increase in the oxygen levels in the seas and air. What was (were) the major consequence(s) of that change?
I. aerobic respiration became the major mode of life
II. all anaerobic organisms went extinct
III. formation of ozone layer

Question

Quizplus · Accepted Answer

The increase in oxygen levels allowed aerobic respiration to become more widespread and led to the formation of the ozone layer, which protected life from harmful UV radiation. Not all anaerobic organisms went extinct; some adapted to oxygen-poor environments.

Increase in the Population of Photosynthetic Bacteria Using the Oxygen-Releasing