The alfalfa plant has a symbiotic relationship with nitrogen-fixing bacteria called rhizobia. Based on your understanding of nitrogen fixation, what predictions can you make about this symbiotic relationship?
Alfalfa provides rhizobia with a completely anaerobic environment.
Alfalfa produces an oxygen-binding heme protein in their root nodules.
Rhizobia produce more ammonia than free-living (nonsymbiotic) bacteria do.
Rhizobia provide alfalfa with citric acid cycle intermediates.
Which chemical transformation occurs during nitrogen assimilation?
reduction of NO2- to form NH3
oxidation of NH3 to form NO2-
oxidation of NO2- to form NO3-
reduction of NO2- to form NO3-
reduction of N2 to form NH3