Consider the following:
- Photosynthesis
- Respiration
- Decay of organic matter
- volcanic action
Which of the above add carbon dioxide to the carbon cycle on Earth?
[UPSC Civil Services Exam – 2011 Prelims]
(a) 1 and 4 only
(b) 2 and 3 only
(c) 2, 3 and 4 only
(d) 1, 2, 3 and 4
Answer: (c)
Explanation:
Sources of Carbon Dioxide in the Carbon Cycle:
- Volcanic action
- Respiration
- Decomposition
Photosynthesis takes up Carbon dioxide and releases oxygen, but it does not add carbon dioxide to the carbon cycle.