Q. $Nostoc$ fixes dinitrogen in symbiotic association with the following I. $Alnus$ II. $Gunnera$ III. $Anthoceros$ IV. $Casuarina$
A) I and II
B) II and III
C) I and III
D) I and IV
Explanation
$Nostoc$ is a blue-green alga or cyanobacterium. It is filamentous and in most cases colonial blue-green alga. It occurs in free state as well as in symbiotic association with Anthoceros (a bryophyte) or with Gunnera manicata (an angiospermic marsh plant).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.