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Topic

Biofertilizer

Asked 2 times in CSE over 9 years (2001–2010), peaking in 2001.
2
PYQs
1
Exams
2
Years active
2001–2010
Span
2001
Peak
1/2
Answers
📅 Full chronological timeline →

Key insights

  • Most tested in CSE — 2 of 2 PYQs
  • Most asked in 2001
  • Recurs across 2 years (2001–2010)

Across exams

CSE · 2

How the concept evolved

101
110
Largely a pre-2016 idea — watch for a comeback.

Related concepts

Ideas UPSC tests alongside this one — keep exploring.

Sample questions

You've seen the pattern — here are a few of the actual PYQs.
CSE2010
Which feature of some species of blue-green algae helps promote them as bio-fertilizers?
  1. A They convert atmospheric methane into ammonia which the crop plants can absorb readily
  2. B They induce the crop plants to produce the enzymes which help convert atmospheric nitrogen to nitrates
  3. C They have the mechanism to convert atmospheric nitrogen into a form that the crop plants can absorb readily
  4. D They induce the roots of the crop plants to absorb the soil nitrates in larger quantities
Answer key not yet available (pending official release)
Science & Technology › Biotech & Genetics
CSE2001
Which one of the following organisms can serve as a biofertilizer for rice crop? (2001)
  1. A Blue-green algae ✓
  2. B Rhizobium sp
  3. C Mycorrhizal fungi
  4. D Azotobacter sp
✓ Correct answer: (A)
Agriculture › Soils & Inputs

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