Question

Nitrogen fixer soil organisms belong to
(a) mosses (b) bacteria
(c) green algae (d) soil fungi

Answer 1

Explanation:

The answer is option b. bacteria.

Answer 2

The required "option b) bacteria" is correct.

Explanation:

The atmospheric nitrogen($N_{2}$) is not available for the plants. By the process of nitrogen fixation, atmospheric nitrogen is converted into ammonia($NH_{3}$) and made available for plants. The nitrogen fixer soil organisms belong to bacteria.

Examples of free-living nitrogen-fixing bacteria include cyanobacteria, Azotobacter, Clostridium.

For examples of symbiotic nitrogen-fixing bacteria include Rhizobium, Bradyrhizobium.

Thus, the required "option b) bacteria" is correct.