Question

The sharp rise in atmospheric oxygen concentration beginning about 0.8 Ga is important because it:

1) made possible the explosion of life recorded in the fossil record beginning about 0.58 Ga
2) increased the rate of formation of iron sulfide minerals
3) caused a sharp decline in the abundance of plants
4) caused the Earth to start spinning faster on its axis of rotation
5) caused the temperature of the Earth to increase

Answer 1

The significant increase in atmospheric oxygen around 0.8 Ga enabled an explosion of life around 0.58 Ga by supporting aerobic respiration and creating a protective ozone layer.

Step-by-step explanation:

The sharp rise in atmospheric oxygen concentration beginning about 0.8 billion years ago (0.8 Ga) was an important milestone in Earth's history because it made possible the explosion of life recorded in the fossil record beginning about 0.58 billion years ago (0.58 Ga). Its significance lies in the fact that the accumulation of oxygen in the atmosphere facilitated the development of aerobically respiring organisms and created an environment suitable for more complex life forms. In addition to this, the production of oxygen also led to the formation of the ozone layer, which protected the surface from harmful ultraviolet radiation, allowing life to move onto land.