They train our immune system so it's ready when our bodies are attacked, and they aid in digestion and supply us with vitamins. ... Scientists and doctors can even utilize prokaryotes to help the human body.
The best answer to go with is b you’re welcome
Answer:
The unified cell theory states that: all living things are composed of one or more cells; the cell is the basic unit of life; and new cells arise from existing cells. Rudolf Virchow later made important contributions to this theory.
Explanation:
They don't need to be near water for reproductive purposes!
