Question

The process of conversion of atmospheric free N2 gas to nitrogenous compounds like NH3 is termed as
A. Nitrification
B. Nitrate reduction
C. Nitrogen fixation
D. Ammonification

Answer 1

Hint: Nitrogen fixation is the process by which the atmospheric nitrogen is converted in either a natural or an industrial means to a form of nitrogen such as ammonia. Naturally, most nitrogen is harvested from the atmosphere by microorganisms to form ammonia, nitrites, and nitrates that can be used by the plants.

Complete answer: Nitrogen fixation- Any natural or industrial process that causes free nitrogen, which is a relatively inert gas plentiful in air, to combine chemically with other elements to form more-reactive nitrogen compounds such as ammonia, nitrates, or the nitrites. This fixation converts the nitrogen in the atmosphere into forms that plants can absorb through their root systems. Nitrogen fixation is the conversion of inert atmospheric nitrogen into utilizable compounds of nitrogen like nitrate, ammonia, amino acids. Nitrogen fixation can be atmospheric, industrial, or biological.
Therefore, the answer is option C.
-Nitrification is the microbial process by which reduced nitrogen compounds are sequentially oxidized to nitrite and nitrate.
-Ammonia is present in the drinking water through either naturally-occurring processes or through ammonia addition during the secondary disinfection to form chloramines.
-Nitrate reduction- The reduction of nitrate is generally anaerobic respiration in which an organism derives its oxygen from the nitrate.
-Ammonification- This refers to any chemical reaction in which amino groups are converted into ammonia or its ionic form, as an end product. The bacteria and related microorganisms derive the metabolically useful energy from the oxidation of organic nitrogen to the ammonium.

Note: The nitrogen cycle is the flow of organic and inorganic nitrogen within an ecosystem where there is an interchange between the nitrogenous compounds and the atmospheric nitrogen.
The atmospheric nitrogen can be converted directly into nitrogen compounds by nitrogen-fixing bacteria.