Q. Which of the following is common to $Azospirillum,\ Anabaena,\ Nostoc$ and $Oscillatoria$
A) $N_{2}$-fixer microbes
B) Prokaryotic organism
C) Both (a) and (b)
D) Eukaryotic organism
Explanation
Azospirillum is a Gram negative, free living bacteria, which absorb free nitrogen from soil and air and convert it into salts of nitrogen like amino acids and enrich soil nutrients. Nostoc, Anabaena and Oscillatoria fix atmospheric nitrogen and increase the organic matter of the soil through their photosynthetic activity
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.