Question: What would happen if bacteria ceased to exist?

Rebecca Cook answered on 22 Jun 2013:

Every other living thing would probably also cease to exist. Cyanobacteria are very important bacteria that carry out photosynthesis and therefore produce the oxygen which supports most animals on earth. Other bacteria are important for making use of nitrogen in the air and creating nitrogen compounds that are needed to support plant life. So, bacteria are pretty vital for animals and plants.