Which one of the following four statements is true regarding nitrogen fixation by bacteria?
1
Nitrogen fixation is primarily an oxidation process requiring continuous supply of electron acceptors.
2
Molybdenum accepts, but cannot donate, electrons within nitrogenase.
3
Symbiotic nitrogen fixers have a respiratory mechanism for protecting nitrogenase.
4
Nitrogen fixation is inhibited in some bacteria due to depletion of carbon source.
5
Question Not Attempted