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 role did cyanobacteria play in the history of Earth's atmosphere?

Describe the process of photosynthesis as it relates to cyanobacteria.

How did the increase in oxygen levels affect life on Earth?

What was the Great Oxygenation Event and what were its consequences?

Explain the significance of endosymbiosis in the evolution of plant cells.