What is the nitrogen cycle

the series of processes by which nitrogen and its compounds are interconverted in the environment and in living organisms, including nitrogen fixation and decomposition.

Explanation:

The nitrogen cycle describes how nitrogen moves between plants, animals, bacteria, the atmosphere, air, and soil in the ground.

during the process of dna replication, brdu can replace thymidine and incorporate into the newly synthesized dna, cell proliferation thus can be reflected in the extent of brdu incorporation.