Which process in the nitrogen cycle converts ammonia to nitrate?

Which process in the nitrogen cycle converts ammonia to nitrate?

• A. Denitrification
• B. Nitrogen fixation
• C. Nitrification
• D. Assimilation

Answer: (C)

Nitrification is the process being tested. It’s the microbial oxidation of ammonia to nitrate in the nitrogen cycle. Ammonia (NH3/NH4+) from decomposition is first converted to nitrite by bacteria such as Nitrosomonas, then nitrite is converted to nitrate by bacteria like Nitrobacter. This step is important because nitrate is a form plants can readily take up to build organic compounds. Other processes differ: denitrification moves nitrate back to gaseous N2 under low-oxygen conditions, nitrogen fixation converts atmospheric N2 into ammonia, and assimilation is the uptake of inorganic nitrogen by plants.

Nitrification is the process being tested. It’s the microbial oxidation of ammonia to nitrate in the nitrogen cycle. Ammonia (NH3/NH4+) from decomposition is first converted to nitrite by bacteria such as Nitrosomonas, then nitrite is converted to nitrate by bacteria like Nitrobacter. This step is important because nitrate is a form plants can readily take up to build organic compounds. Other processes differ: denitrification moves nitrate back to gaseous N2 under low-oxygen conditions, nitrogen fixation converts atmospheric N2 into ammonia, and assimilation is the uptake of inorganic nitrogen by plants.