Question

Nitrogen fixing bacteria-anabaena-are found in the plant ______.
A. Azolla leaves
B. Cycas coralloid roots
C. Anthoceros body
D. All of these.

Answer 1

Hint: Anabaena Azollae manages a mutually beneficial symbiotic relationship with the water fern Azolla. It gives the cyanobacteria with safe surroundings in exchange for nitrogen.

Complete answer:
To solve this question, at first, we have to know that nitrogen fixing bacteria are present in which type of plants. Anabaena is a filamentous cyanobacteria that exists as plankton. They are known for nitrogen-fixing capabilities, and that they develop symbiotic relationships with some specific plants, which includes the mosquito fern.

Now lets us find the solution from given options -
Azolla floats on the surface of water by numerous small, intently overlapping scale-like leaves, with their roots hanging in the water. They develop a symbiotic relation with the cyanobacterium Anabaena Azollae, which fixes nitrogen present in the atmosphere, helping the plant to get the vital nutrient.
Cycas has unbranched, coral-like, apogeotropic coralloid roots, which harbour nitrogen-solving colonies of cyanobacteria, like Anabaena. It fulfills the energy requirement of nitrogen fixers via constant carbon in exchange for fixed nitrogen. The bacteria stay as endosymbionts inside the roots.
Anthoceros has a thallus body. It is lobed and it has abnormal or dichotomous branches. Anabaena Are the only sort of cyanobacteria, found in anthoceros bodies. They perform symbiotic Nitrogen fixation.

Thus, the right answer is option D. i.e. All of these.

Note: Anabaena is filamentous cyanobacteria present generally in shallow waters with nitrogen fixing capability. They are generally observed in symbiotic relation with plants like mosquito ferns.