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Topic Carbon cycle
Asked 2 times across 2 UPSC exams over 10 years (2014–2024), peaking in 2014.
Key insights
- Most tested in CSE — 1 of 2 PYQs
- Most asked in 2014
- Recurs across 2 years (2014–2024)
How it travelled across exams
First appearance in each exam — the same idea, reframed.
CSE 2014 → ESE 2024
How the concept evolved
Long-running — most appearances (1 of 2) predate 2016, and it still returns.
Sample questions
You've seen the pattern — here are a few of the actual PYQs.
ESE2024
Which one of the following statements is NOT correct regarding carbon dioxide?
- A Carbon dioxide is given off when dead organisms and other organic materials decompose
- B When volcanoes erupt, they give off carbon dioxide that is stored in the mantle
- C Ocean water releases dissolved carbon dioxide into the atmosphere when water temperature rises
- D A good amount of carbon in the atmosphere is present as methane gas ✓
✓ Correct answer: (D)
Environment & Ecology › Climate Change
CSE2014
Which of the following adds/add carbon dioxide to the carbon cycle on the planet Earth?
- Volcanic action
- Respiration
- Photosynthesis
- Decay of organic matter
Select the correct answer using the code given below.
- A 1 and 3 only
- B 2 only
- C 1, 2 and 4 only ✓
- D 1, 2, 3 and 4
✓ Correct answer: (C)
Environment & Ecology › Ecology & Ecosystems
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