Red pigment $(Leghaemoglobin)$ having affinity for oxygen is present in the roots of

We find that $Rhizobium$ forms nodules on the roots of leguminous plants. Also,$Frankia$,another microbe,forms nitrogen-fixing nodules on the roots of the non-leguminous plant $Alnus$. Is it necessary for a microbe to be in close association with a plant to provide mineral nutrition? Explain with the help of one example.

In which of the following are root nodules found?

Assertion : Leguminous plants are nitrogen fixers.
Reason : Leguminous plants have $Rhizobium$ in their root nodules.

Members of the bean family are particularly important for crop rotation because:

Rhizobium lives symbiotically with root nodules and fixes atmospheric nitrogen. It provides nitrogenous compounds to the host and in turn takes food from the host. This food taken by the bacterium is: