Biogeochemical Cycles & Earth Systems

8 questions in Environment & Ecology.

Asked in 2025, 2021, 2014, 2013, 2011, 2010, 2002

2025 · Q40 Environment & EcologyBiogeochemical Cycles & Earth Systemsmoderate

With reference to the planet Earth, consider the following statements : I. Rain forests produce more oxygen than that produced by oceans. II. Marine phytoplankton and photosynthetic bacteria produce about 50% of world's oxygen. III. Well-oxygenated surface water contains several folds higher oxygen than that in atmospheric air. Which of the statements given above is/are correct?

(a)I and II
(b)II only
(c)I and III
(d)None of the above statements is correct

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Official answer(b) II only

2021 · Q27 Environment & EcologyBiogeochemical Cycles & Earth Systemseasy

In case of which one of the following biogeochemical cycles, the weathering of rocks is the main source of release of nutrient to enter the cycle?

(a)Carbon cycle
(b)Nitrogen cycle
(c)Phosphorus cycle
(d)Sulphur cycle

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Official answer(c) Phosphorus cycle

2014 · Q19 Environment & EcologyBiogeochemical Cycles & Earth Systemsmoderate

Which of the following adds/add carbon dioxide to the carbon cycle on the planet Earth? 1. Volcanic action 2. Respiration 3. Photosynthesis 4. 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

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Official answer(c) 1, 2 and 4 only

2013 · Q34 Environment & EcologyBiogeochemical Cycles & Earth Systemsmoderate

Which of the following adds/add nitrogen to the soil? 1. Excretion of urea by animals 2. Burning of coal by man 3. Death of vegetation Select the correct answer using the codes given below.

(a)1 only
(b)2 and 3 only
(c)1 and 3 only
(d)1, 2 and 3

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Official answer(c) 1 and 3 only

2011 · Q21 Environment & EcologyBiogeochemical Cycles & Earth Systemsmoderate

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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Official answer(b) 2 only

2011 · Q48 Environment & EcologyBiogeochemical Cycles & Earth Systemseasy

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

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Official answer(c) 2, 3 and 4 only

2010 · Q74 Environment & EcologyBiogeochemical Cycles & Earth Systemseasy

Which one of the following reflects back more sunlight as compared to the other three?

(a)Sand desert
(b)Paddy crop land
(c)Land covered with fresh snow
(d)Prairie land

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Official answer(c) Land covered with fresh snow

2002 · Q136 Environment & EcologyBiogeochemical Cycles & Earth Systemsmoderate

Consider the following ecosystems: 1. Taiga 2. Tropical evergreen 3. Tropical deciduous 4. Tundra The correct sequence in decreasing order of the albedo values of these ecosystems is

(a)1, 4, 3, 2
(b)4, 1, 2, 3
(c)4, 1, 3, 2
(d)1, 4, 2, 3

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Official answer(c) 4, 1, 3, 2