When scientists classify living things, they do not include viruses. this is because viruses

The correct answer is- Viruses can not reproduce by their own.

Viruses are non cellular, microscopic, infectious, non living agents, primarily composed of nucleic acid ( which could be DNA or RNA) that is surrounded by a coat of protein called capsid. They are not composed of cell and can not produce energy by themselves.

They lack a machinery for replicating their genetic material and therefore require a body of specific host ( such as bacteria) where they can replicate their genome and produce more viral copies.

Thus, scientist do not include virus while classifying living things.

step 1: nitrogen fixation- conversion of atmospheric no₂ into forms useful to plants by lightning, bacteria, and cyanobacteria.

step 2: nitrification-process of converting ammonia to nitrite or nitrate.

step 3: assimilation-plant roots absorb new form of nitrogen.

step 4: ammonification-conversion of organic nitrogen to ammonia by bacteria involved in decomposition.

step 5: denitrification-bacteria turns the decomposed matter back into n₂o, which is released into atmosphere; repeat cycle.

the answer is c.mitochondria. glad to .