Question

The largest reservoir of nitrogen is found in which of the following?

A. earthworms
B. marine organisms
C. atmosphere
D. trees

Answer 1

The answer is C. atmosphere.

An atmosphere contains about 78 percent of nitrogen gas. In animals plants, nitrogen can be found as a part of some macromolecules (proteins, nucleic acids), but in much smaller amount than in the atmosphere, which is the highest nitrogen source.