UPSC CSE Prelims
Question 97
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.
View correct answer and explanation
Correct answer: C
Correct Option: C
Explanation: Volcanic activity, respiration and decomposition emit carbon dioxide; photosynthesis generally takes CO₂ out of the atmosphere.
Statement/Pair-wise Analysis:
Statement/Item 1: Correct - Volcanoes release geologically stored carbon dioxide.
Statement/Item 2: Correct - Respiration oxidises organic matter and releases CO₂.
Statement/Item 3: Incorrect - Photosynthesis fixes CO₂ into organic molecules, rather than adding CO₂.
Statement/Item 4: Correct - Microbial breakdown of organic matter can liberate CO₂.
Option-wise Analysis:
A: Incorrect - includes incorrect statement/item 3; omits correct statement/items 2, 4.
B: Incorrect - omits correct statement/items 1, 4.
C: Correct - includes all and only the correct items.
D: Incorrect - includes incorrect statement/item 3.