Class 12 NEET Biology Microbes in Human Welfare

(d) : Members of Kingdom Monera - bacteria and cyanobacteria (blue green algae) have the ability to fix nitrogen. Azotobacter is a N2 -fixing bacteria. Anabaena and Nostoc are heterocystous blue-green algae. The heterocysts are the sites of N2 -fixation. Spirogyra is one of the commonest green algae. It has no function in nitrogen fixation.