Why are bacteria a necessary part of the nitrogen cycle?
A. Other living things cannot use atmospheric nitrogen.
B. Other living things cannot use the nitrogen in plants.
C. Bacteria are the main nitrogen reservoir.
D. Bacteria are the main nitrogen transpirators.

Bacteria - a necessary part of the nitrogen cycle

Explanation:

Bacteria form an integral part in the nitrogen cycle in trapping the atmospheric nitrogen; whereas, other organisms are incapable of trapping or utilizing the atmospheric nitrogen.

Bacteria act as nitrogen transpirator (fixers) and as nitrogen reservoir for the other living organisms.

Bacteria takes part in most part of the nitrogen cycle;

Nitrogen-fixing bacteria

Nitrifying bacteria

Denitrifying bacteria

Decomposing or decay bacteria

According to their lifestyle, bacteria takes part in nitrogen cycle. The free-living, phototropic, and aerobic bacteria like cyanobacteria; symbiotic chemoorganotropic, aerobic bacteria like rhizobium; the anerobic and chemolithotropic like Methanococcus species have their unique role in nitrogen cycle.

plato users:

d.  

there was a variety of food available on island x, but there were only large seeds and nuts on island y.