Question

Why are bacteria a necessary part of the nitrogen cycle

Answer 1

They help convert nitrogen to nitrate which is usable by living beings. (Living beings can't use regular nitrogen)

Answer 2

Bacteria is important to the nitrogen cycle because it breaks nitrogen down that is in the soil into a more simpler form that plants can use.

If bacteria didn't, plants wouldn't be able to intake the nitrogen and do photosynthesis, so we wouldn't get oxygen.