Question

Some blue green algae can be used as biofertilizer as they are

• A. Photosynthetic
• B. Surrounded by mucilage
• C. Growing every where
• D. Capable of fixing nitrogen

Answer 1

The correct option is D Capable of fixing nitrogen

Some blue-green algae can fix atmospheric nitrogen because they contain an O${}_2$ sensitive enzyme nitrogenase. They live in close association with the roots of the plant and fix the atmospheric nitrogen into the soluble form which is utilized by the plant.

So, the correct answer is option D.