TED-Ed: How a single-celled organism almost wiped out life on Earth - Anusuya Willis

Cyanobacteria, ancient single-celled organisms, were pivotal in Earth's history by introducing free oxygen into the atmosphere through photosynthesis. This led to the Great Oxygenation Event, causing a mass extinction and a global ice age. Over time, life adapted, leading to the evolution of complex organisms. Cyanobacteria also played a role in the development of plant cells through endosymbiosis. Today, they continue to influence Earth's ecosystems by producing oxygen and fixing nitrogen.

What was the primary atmospheric composition of Earth 3.5 billion years ago?

• Methane and hydrogen

• Oxygen and carbon dioxide

• Nitrogen, carbon dioxide, and methane

• Oxygen and nitrogen

What evolutionary development allowed cyanobacteria to thrive and alter Earth's atmosphere?

• Photosynthesis

• Endosymbiosis

• Anaerobic respiration

• Nitrogen fixation

What was the significant event caused by the accumulation of oxygen in Earth's atmosphere?

• The Cretaceous-Paleogene Extinction

• The Great Oxygenation Event

• The Permian Extinction

• The Cambrian Explosion

How did the increase in atmospheric oxygen affect Earth's climate during the Great Oxygenation Event?

• It had no significant impact

• It caused global warming

• It led to the Huronian Glaciation

• It increased volcanic activity

What process led to the formation of plant cells from cyanobacteria?

• Nitrogen fixation

• Endosymbiosis

• Photosynthesis

• Anaerobic respiration