Question

The process of converting ammonia into nitrate by soil bacteria is called as:

• A. Mineralization
• B. Nitrification
• C. Nitrogen fixation
• D. Immobilization

Hint:

Remember the nitrogen cycle steps: Fixation (gas to ammonia), Nitrification (ammonia to nitrate), and Denitrification (nitrate to gas). This question asks about the middle step.

Answer 1

The Correct Option is B

Nitrification is a two-step biological process in which ammonia ($NH_3$) or ammonium ($NH_4^+$) is oxidized first to nitrite ($NO_2^−$) by bacteria like \textit{Nitrosomonas}, and then the nitrite is oxidized to nitrate ($NO_3^−$) by bacteria like \textit{Nitrobacter}. Nitrate is the primary form of nitrogen used by plants.