UPSC 2011 › Environment & Ecology › Biogeochemical Cycles & Earth Systems

2 questions · 2011 · answers as per the UPSC key

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UPSC 2011 · Q21 · Environment & Ecology › Biogeochemical Cycles & Earth Systems · Save

Human activities in the recent past have caused the increased concentration of carbon dioxide in the atmosphere, but a lot of it does not remain in the lower atmosphere because of

  1. Its escape into the outer stratosphere,
  2. The photosynthesis by phytoplankton in the oceans,
  3. The trapping of air in the polar ice caps.

Which of the statements given above is/are correct?

(a) 1 and 2
(b) 2 only
(c) 2 and 3
(d) 3 only
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Answer: (b) 2 only
UPSC 2011 · Q48 · Environment & Ecology › Biogeochemical Cycles & Earth Systems · Save

Consider the following :

  1. Photosynthesis
  2. Respiration
  3. Decay of organic matter
  4. Volcanic action

Which of the above add carbon dioxide to the carbon cycle on Earth ?

(a) 1 and 4 only
(b) 2 and 3 only
(c) 2, 3 and 4 only
(d) 1, 2, 3 and 4
Show answer
Answer: (c) 2, 3 and 4 only