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Topic Cellular respiration
Asked 8 times across 4 UPSC exams over 7 years (2018–2025), peaking in 2020.
Key insights
- Most tested in CDS — 4 of 8 PYQs
- Most asked in 2020
- Recurs across 5 years (2018–2025)
How it travelled across exams
First appearance in each exam — the same idea, reframed.
CDS 2018 → CAPF 2020 → NDA 2024 → GEO 2025
How the concept evolved
Rising — more than half its appearances (8 of 8) are since 2016.
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.
CDS2025
How many Carbon atoms are present in a Pyruvate molecule ?
- A 2
- B 3 ✓
- C 4
- D 5
✓ Correct answer: (B)
Science & Technology › Biology & Health
GEO2025
Which one of the following reactions correctly represents the respiration reaction?
- A 2H₂ + O₂ → 2H₂O
- B C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O ✓
- C CH₄ + 2O₂ → CO₂ + 2H₂O
- D C₆H₁₂O₆ + H₂O → C₆H₁₂O₇ + H₂
✓ Correct answer: (B)
Science & Technology › Physics & Chemistry
NDA2024
Which one among the following is the source of energy in cells ?
- A ADP
- B ATP ✓
- C AMP
- D NAD
✓ Correct answer: (B)
Science & Technology › Biology & Health
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