Question

What is wrong about Frankia?
A. Can induce root formation in many plants.
B. Cannot fix vesicles in which nitrogenase is protected from oxygen by a chemical barrier of triterpene hopanoids.
C. Cannot fix nitrogen in living state
D. Like Rhizobium bacteria, these infect the host by deforming the root hair and stimulating cell proliferation in the cortex of the host.

Answer 1

Hint: Frankia are nitrogen fixing bacteria. They belong to the group actinomycetes and are similar to Rhizobium. These are the filamentous microsymbionts which are found in the roots of the non leguminous plants.

Complete answer:
To know the correct answer to the question, we must be well aware of Frankia.
Frankia is a gram-positive bacterium which induces root formation in many plants. It has thick cell walls which are made up of peptidoglycans.
Like Rhizobium bacteria, these usually infect the host by deforming root hair and stimulating cell proliferation in the cortex of the host.
Frankia cannot fix vesicles in which nitrogenase is protected from oxygen by a chemical barrier of triterpene hopanoids.

Therefore, the correct answer to the question is option c i.e it cannot fix nitrogen in the living state. This statement is incorrect with regards to Frankia.

Note: Here, it must be noted that Frankia live freely in the soil but these fix the dinitrogen only when they are in a symbiotic association with other plants. Frankia is usually found associated with the actinorhizal plants. There they fix the atmospheric nitrogen with the help of an enzyme known as nitrogenase through the process of nitrogen fixation.