Question

Study the given biogeochemical cycle and identify the steps (i) and (ii).

• A. (i)- Ammonification, (ii)- Denitrification
• B. (i)- Denitrification, (ii)- Ammonification
• C. (i)- Nitrification, (ii)- Ammonification
• D. (i)- Ammonification, (ii)- Nitrification

Answer 1

Answer: (A)

(i)- Ammonification, (ii)- Denitrification

Nitrogen fixation is a process by which nitrogen in the Earth's atmosphere is converted into ammonia (NH${}_3$) or related nitrogenous compounds. Atmospheric nitrogen, which is molecular dinitrogen (N${}_2$), is relatively unreactive and is metabolically useless to all but a few microorganisms. The fixation process converts N${}_2$ into ammonia, which is metabolized by most organisms.Nitrogen fixation is essential to life because fixed inorganic nitrogen compounds are required for the biosynthesis of all nitrogen-containing compounds. Therefore, as part of the nitrogen cycle, it is essential for agriculture and the manufacture of fertilizer. It is also, indirectly, relevant to the manufacture of all chemical compounds that contain nitrogen, which includes explosives, most pharmaceuticals, and dyes.

Ammonification: This is a process where bacteria or other decomposers break down nitrogen-containing chemicals from waste or a dead body into simpler chemicals, such as ammonia.

Denitrification: This process is opposite of nitrification. Bacteria not exposed to oxygen take in nitrates and break it down into nitrites, then into nitrogen gas. The nitrogen gas is released back into the atmosphere. This process is meant to balance out the process of nitrification and maintain a steady flow of nitrates, nitrites and nitrogen gas throughout the entire nitrogen cycle.

So the correct option is '(i)- ammonification, (ii)- denitrification'