Question

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

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

Answer 1

Answer: (D)

Capable of fixing nitrogen

Some cyanobacteria can fix atmospheric nitrogen in anaerobic conditions by means of specialized cells called heterocysts. These heterocyst forming species are specialized for nitrogen fixation, and are able to fix nitrogen gas into ammonia, nitrites, or nitrates, which can be absorbed by plants and converted to proteins and nucleic acids as nitrogen cannot be directly absorbed by plants. Therefore, some of the cyanobacterial species are used as biofertilizers.

So, the correct answer is 'Capable of fixing nitrogen'