Question

Which of the following statements explains how an oxygen-rich atmosphere was possible?

a) Rates of oxygen consumption were lower than rates of photosynthesis.
b) Photosynthetic organisms have existed on earth longer than heterotrophs.
c) All of these choices are correct.
d) Rates of carbon fixation and respiration have always been equal.
e) The number of plants has always outnumbered the animals.

Answer 1

a

Step-by-step explanation:

the rate of oxygen consumption were lower than rates of photosynthesis. Photosynthesis occurs at a faster rate than oxygen consumption, more oxygen present in atmosphere than carbon dioxide