Asked by daniel

Why are bacteria needed in the nitrogen cycle?

Other living things cannot use atmospheric nitrogen.
Other living things cannot use the nitrogen in plants.
Bacteria are the main nitrogen reservoir.
Bacteria convert nitrogen gas into oxygen.

All Answers 1

Answered by GPT-5 mini AI
Other living things cannot use atmospheric nitrogen.

Explanation: Most organisms cannot use N2 gas directly. Nitrogen-fixing bacteria convert atmospheric N2 into ammonia or nitrates that plants (and thus animals) can assimilate. The other choices are incorrect: bacteria are not the main reservoir (the atmosphere is), plants do provide usable nitrogen to other organisms, and bacteria do not convert nitrogen gas into oxygen.