Explain why cyanobacteria were important to the development of life on earth.

Cyanobacteria are blue-green algae that produce chlorophyll and undergo photosynthesis. Oxygen, a byproduct of that photosynthesis, was released into the atmosphere, changing it in such a way that it may have allowed the evolution of more complex forms of life.

i think the answer is gold im not entirely sure

you can have just about every answer you can think of