Diazotrophs maximize nitrogenase activity by
A) closely coupling N₂ fixation with high rates of photosynthesis.
B) fixing N₂ at times when oxygen is absent or in low concentrations.
C) producing specialized structures to protect nitrogenase from oxygen.
D) producing specialized structures or fixing N₂ at times when oxygen is absent to protect nitrogenase from oxygen.

Question

Quizplus · Accepted Answer

Diazotrophs typically produce specialized structures such as heterocysts or fix N₂ at times when oxygen is absent to protect nitrogenase from oxygen. This is because nitrogenase is a highly oxygen-sensitive enzyme and requires an oxygen-free environment to function properly.

Diazotrophs Maximize Nitrogenase Activity by