key term - Oxygen Revolution

Definition

The Oxygen Revolution, also known as the Great Oxidation Event, marks the period in Earth's history when oxygen levels significantly increased due to photosynthetic microorganisms. This led to drastic changes in the biosphere and the evolution of aerobic life.

5 Must Know Facts For Your Next Test

1. Occurred approximately 2.4 billion years ago.
2. Triggered by cyanobacteria performing oxygenic photosynthesis.
3. Led to the formation of an ozone layer, which protected life from harmful UV radiation.
4. Caused a mass extinction of anaerobic organisms that were unable to survive in high-oxygen environments.
5. Enabled the development and diversification of aerobic (oxygen-dependent) organisms.

Review Questions

Related terms

Cyanobacteria:

Photosynthetic bacteria that contributed to the increase in atmospheric oxygen.

Aerobic Organisms: Organisms that require oxygen for survival and energy production.

Anaerobic Organisms: Organisms that do not require oxygen for growth and may even die in its presence.