Question

0.71. Which of the followings is a group of biological nitrogen
fixing group of fungi?
a. Nostacles
b. Actinomycetes
c Casurina
d. Cycas​

Answer 1

Answer:

nostacles are in the group

Answer 2

Answer:

None of them is a group of biological nitrogen-fixing fungi.

Explanation:

Nitrogen available in the atmosphere is inert and can not be utilized by the pants for its metabolism directly. Plants lack the enzymes Nitrogenase needed for atmospheric nitrogen fixation. Nitrogen fixation helps plants to make use of nitrogen for plant growth. Nitrogen fixation takes place by two processes in nature:

Lightning or ultraviolet rays: converts atmospheric nitrogen into nitric oxide. Biological Nitrogen fixation: done by 2 groups of bacteria:

Free-living nitrogen fixers: Anabaena, Cyanobacteria etc. which are asymbiotic nitrogen-fixing bacteria.

Symbiotic Nitrogen fixers: lives in a symbiotic relationship with the roots of the leguminous plants like peas, alfalfa by forming root nodules. The root nodules provide protection and food to them and the symbiotic bacteria fix nitrogen for the plant. Example: Rhizobium and different species of Azospirillum.

Nostacles are filamentous genera that belong to the order of cyanobacteria, lives inside the heterocyst and are obligate anaerobic nitrogen-fixers.

Actinomycetota is a phylum of unicellular filamentous bacteria which are nitrogen fixers. They form a symbiotic association with leguminous plants.

Casurina is a genus of trees and Cycas is a genus of plants.