Leghaemoglobin occurs in

What type of bacteria are $Rhizobium$ and $Frankia$?

Leghemoglobin is found in which one of the following organisms?

The anaerobic condition for nitrogen fixation is maintained by ..........

The pigment leghaemoglobin is present in the roots of

Select the correct statements from the given:
$(a)$ Nitrogenase is a heterodimeric protein.
$(b)$ Root hairs curl by action of nitrogenase and plant 'nod factors'.
$(c)$ During symbiotic $N_2$ fixation,$ATP$ is provided by the legume plant.