MCQs on Carbon cycle

1. This factor contributes to the carbon cycle
(a) fossil fuel combustion
(b) respiration
(c) photosynthesis
(d) all of these
Answer: (d)
2. The source of carbon to plants in the carbon cycle is
(a) fossil fuels
(b) carbonate rocks
(c) atmospheric carbon dioxide
(d) all of the above
Answer: (c)
3. The role of bacteria in the carbon cycle is
(a) Breakdown of organic compounds
(b) Chemosynthesis
(c) Photosynthesis
(d) Assimilation of nitrogen compounds
Answer: (a)
4. In the carbon cycle, the human body returns carbon to the atmosphere through this way:
(a) formation of glucose
(b) waste products
(c) photosynthesis
(d) cellular respiration
Answer: (d)
5. Respiration and photosynthesis are central to this process
(a) nitrogen cycle
(b) phosphorous cycle
(c) carbon cycle
(d) sulphur cycle
Answer: (c)
6. The difference between the phosphorous cycle and carbon cycle lies in the fact that
(a) the phosphorous cycle does not include a gaseous phase but the carbon cycle does
(b) phosphorous does not enter living entities but carbon enters
(c) the phosphorous cycle includes a solid phase, the carbon cycle does not
(d) primary reservoir of the phosphorous cycle is the atmosphere, but rocks are the primary reservoirs for carbon cycle
Answer: (a)
7. Most of the global warming is due to the perturbation of which of these cycles?
(a) Global nitrogen cycle
(b) Global carbon cycle
(c) Global water cycle
(d) All of these cycles equally contribute
Answer: (b)
8. This carbon isotope is radioactive and very rare
(a) Carbon – 11
(b) Carbon – 12
(c) Carbon – 13
(d) Carbon – 14
Answer: (d
9. By this method, the majority of carbon moves from the lithosphere to the atmosphere
(a) erosion
(b) deposition
(c) weathering
(d) fossil fuel burning
Answer: (d)
10. These entities sequester most carbon from the atmosphere
(a) Plants
(b) Archaea
(c) Bacteria
(d) Insects
Answer: (a)