Question

Symbiotic nitrogen fixing bacteria belong to
A.Xanthomonas
B.Acetobacter
C.Pseudomonas
D.Rhizobium

Answer 1

Hint: Nitrogen fixing bacteria are the microorganisms that are capable in fixing atmospheric nitrogen to the forms of nitrogen that can be easily absorbed by the plants such as nitrates or nitrites. There are two types of nitrogen fixing bacteria. That are-
1.Free living nitrogen fixing bacteria
2.Symbiotic nitrogen fixing bacteria

Complete step by step answer:
Symbiotic nitrogen fixing bacteria:
The symbiotic nitrogen fixing bacteria invade the root hairs of the host plants.
In the root hairs these bacteria multiply and stimulate the formation of root nodules.
With the root nodules the bacteria convert the atmospheric nitrogen to the ammonia which the host plant can utilize for its development.
These root nodules are formed in the leguminous plants.
The Rhizobium bacteria symbiotically get associated with leguminous plants.
Rhizobium are gram negative bacteria.
Nitrogen fixation is essential because fixed inorganic nitrogen compounds are required for the biosynthesis of all nitrogen containing organic compounds such as amino acids, nucleoside triphosphates, etc.
Therefore, it has been clear from the above discussion that symbiotic nitrogen fixing bacteria belong to Rhizobium.

Hence the correct answer is option(D)

Note: Symbiotic association is a type of close and long term interaction between the two different biological organisms. The organism that is symbiotic association can be of the same species and can be of different species and are called symbionts. In symbiotic association no one gets harmed, both of the members of this kind of association get benefited with this association.