Question

Nitrates and nitrites present in the soil are changed into _____________ by micro-organisms.

Answer 1

Ammonia:

1. Absorption of nitrate by plant roots from the soil is a carrier-mediated, active and energy-dependent process.
2. The nitrates absorbed by plant roots get converted to amino acids and amides before incorporating into proteins and other macromolecules.
3. The reduction of nitrate into ammonia is called nitrogen assimilation.
4. The reaction is catalyzed by the enzyme nitrite reductase.

Final answer: Nitrates and nitrites present in the soil are changed into ammonia by microorganisms.