Question

Azolla pinnate is allowed to grow in rice fields because.

• A. It does not disturb photosynthesis of Rice plants
• B. It provides food to fish
• C. It provides aeration to standing water
• D. It contains Anabaena

Answer 1

Answer: (D)

It contains Anabaena

Azolla free-floating freshwater fern that harbors nitrogen-fixing cyanobacterium Anabaena azollae by symbiosis relationship in its dorsal leaves. It is capable of fixing atmospheric carbon dioxide and nitrogen and is known as a potent nitrogen fixer.

This nitrogen-fixing capacity helps the plant benefit in a positive manner with the increase in yield and size and it served as the nitrogen requirement for rice.