Question

Which of the following is a symbiotic nitrogen fixer?
A. Azolla
B. Glomus
C. Azotobacter
D. Frankia

Answer 1

Hint: In order to first derive the correct answer, you must now understand the meaning of a symbiotic relationship. A symbiotic relation is that relationship which exists between two species and in which at least one of the species benefits.

Complete answer:
As mentioned earlier, a symbiotic relationship occurs between two species and in which one of them benefits. It can be of three types namely mutualistic, commensalistic and parasitic. In the mutual form, both species benefit from the association. In commensalistic association one species is benefitted however the other one is not affected. In parasitism, a particular member thrives inside another member collectively cast the host and the parasite and the parasite may impose harm or may not impose harm to the host. In the case of plants, nitrogen fixation is an extremely important process as it helps the plants to get the supply of nitrogen which is required for their development. This is the process of biological nitrogen fixation and cannot exist without the symbiotic relationship. The bacteria is provided a niche by the plants where it thrives and the bacteria on the other hand, the bacteria gives fixed nitrogen to the plants. Extremely important enzymes that are present in bacteria can only bring about the process of nitrogen faction in plants and hence this process is not possible without these bacteria. Examples of nitrogen fixation bacteria include Nostoc , Anabaena and Frankia among many others.

So, the correct answer is option D Frankia.

Note:
Frankia are a group of nitrogen fixing bacteria which is similar to the bacteria that live in association with actinorhizal plants. It is a filamentous and free living bacteria that also brings about the formation of root nodules in which they fix nitrogen.