Q49 - Biological Nitrogen Fixation - Diazotrophs and Nitrogenase
Only some bacteria and archaea are capable of performing biological nitrogen fixation. Organisms that grow on N₂ as their sole nitrogen source are called diazotrophs and play an essential role in the biosphere.
Determine whether the following statements are true or false:
A. Diazotrophs fix nitrogen in the form of nitric acid.
B. The process of nitrogen fixation consumes a lot of energy.
C. The enzyme nitrogenase which catalyzes nitrogen fixation requires an organic source of nitrogen as a substrate for catalytic activity.
D. Nitrogen fixation requires molecular oxygen.
Question reproduced from IBO 2022, Theoretical Paper 1, licensed under CC BY-NC-SA 4.0 - attributed to the International Biology Olympiad. Open the full exam PDF · Community solutions (unofficial)