In which of the following are root nodules found?

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

What are the conditions necessary for fixation of atmospheric nitrogen by $Rhizobium$? What is their role in $N_2$-fixation?

Leguminous plants are able to fix atmospheric nitrogen through the process of symbiotic nitrogen fixation. Which one of the following statements is not correct during this process of nitrogen fixation?

The nitrogen-fixing symbiotic organism present in $Azolla$ is:

Arrange the stages of root nodule formation in the correct sequence:
$I-$ Infection thread is produced.
$II-$ Bacteria are carried to the cortex of the root.
$III-$ Bacteria attach to the root hair.
$IV-$ Bacteria are released from the thread into the cells.
$V-$ Differentiation into nitrogen-fixing cells occurs.