Q: 8 (IAS/2013)
question_subject:
Science
question_exam:
IAS
stats:
0,55,173,65,55,75,33
keywords:
{'biofertilizers': [0, 1, 0, 2], 'biofertilizer': [1, 0, 0, 0], 'organisms': [4, 1, 3, 2], 'agaricus': [1, 0, 1, 2], 'spirogyra': [2, 0, 0, 1]}
The correct answer is:
2 only - Nostoc.
Nostoc is a cyanobacterium (blue-green algae) that is used as a biofertilizer. It has the ability to fix atmospheric nitrogen and convert it into a form that plants can utilize, thereby enhancing soil fertility.
Agaricus and Spirogyra are not typically used as biofertilizers. Agaricus is a genus of mushrooms, and Spirogyra is a filamentous green algae. While both organisms have ecological importance, they are not commonly employed as biofertilizers.
Therefore, the correct answer is "2 only - Nostoc."