Answer: Glutamine.
- A Glycine
- B Alanine
- C Serine
- D Glutamine
Correct answer: D. Glutamine
Explanation: Glutamine synthetase adds ammonia to glutamate to give glutamine, the first product of ammonia assimilation.
Atmospheric N₂ is fixed into ammonia by nitrogen-fixing bacteria (protected from oxygen by leghaemoglobin in root nodules), converted to nitrate via nitrification for plant uptake, and eventually returned to the atmosphere as N₂ via denitrification, completing the cycle.
Concept context
Essential mineral elements, their roles and deficiency symptoms. Nitrogen fixation and soil nutrition.