GyanGramQuestion
Consider the following organisms:
1. Agaricus
2. Nostoc
3. Spirogyra
Which of the above is/are used as biofertilizer/biofertilizers
PRELIMS 2013 · AGRICULTURE & FOOD SECURITY
Consider the following organisms: 1. Agaricus 2. Nostoc 3. Spirogyra Which of the above i…
Attempt this previous-year question. The correct option stays hidden until you choose.
Pick an option to check yourself.
• Correct Answer: B
• Nostoc is a cyanobacterium with heterocysts containing nitrogenase; it fixes atmospheric N₂ into ammonia and is widely used as a biofertilizer, especially in rice paddies.
• 1 is wrong: Agaricus is a mushroom (decomposer fungus), not a nitrogen fixer. 3 is wrong: Spirogyra is a green alga that only photosynthesizes and lacks nitrogenase.
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