Before the evolution of life produced the process of photosynthesis, small amounts of oxygen were added to the Earth's atmosphere by the process of
A) Respiration
B) Volcanic eruptions
C) Photodissociation of water vapor
D) the formation of banded iron formations
E) latent heat release

Question

Quizplus · Accepted Answer

Photodissociation of water vapor by ultraviolet light in the upper atmosphere can produce small amounts of oxygen before photosynthesis evolved.

Before the Evolution of Life Produced the Process of Photosynthesis