Nitrogen Metabolism — Prelims Questions

Which of the following statements about biological nitrogen fixation is INCORRECT?

Which of the following pairs of bacteria are involved in the two sequential steps of nitrification?

Which enzyme is responsible for the reduction of nitrate to nitrite in plant cells?

The conversion of ammonia to glutamate by reductive amination involves which of the following keto acids?

Which of the following is NOT a free-living nitrogen-fixing bacterium?

Which of the following processes returns nitrogen gas ($N_2$) to the atmosphere, completing the nitrogen cycle?