Question

Why didn't oxygen begin to accumulate in the atmosphere until approximately 1.5 billion years after life appeared on Earth?

A) Early forms of animal life consumed the oxygen.
B) Early forms of plant life consumed oxygen.
C) All the oxygen produced by life went into making the ozone layer.
D) Oxygen produced by life was removed from the atmosphere by oxidation reactions with surface rocks.
E) Oxygen produced by life was removed from the atmosphere by dissolving in the ocean

Answer 1

Oxygen didn't accumulate in the atmosphere until approximately 1.5 billion years after life appeared on Earth because of chemical reactions with Earth's crust and increased erosion.

Step-by-step explanation:

Oxygen didn't begin to accumulate in the atmosphere until approximately 1.5 billion years after life appeared on Earth because chemical reactions with Earth's crust removed the oxygen gas as quickly as it formed. The increasing evolutionary sophistication of life led to a growth in the plant population and increased oxygen production. However, increased geological activity led to heavy erosion on the planet's surface, burying much of the plant carbon before it could recombine with oxygen to form CO₂.