With regard to the bilogical nitrogen fixation by Rhizobium in association with soy bean, which one of the following statement/statements does not hold true?

Answer: ASolution: The enzyme, nitrogenase which is capable of nitrogen reduction is present exclusively in prokaryotes (e.g., Rhiaobium). It is highly sensitive to $O_2$ and gets inactivated when exposed to it, thus does not require oxygen for its functioning. Other statements (b), (c) and (d) are true.