2014 GS Paper I, all questions

UPSC Prelims 2014 · GS Paper I

Question 14: Environment and Ecology

Other than poaching, what are the possible reasons for the decline in the population of Ganges River Dolphins?

  1. 1.Construction of dams and barrages on rivers
  2. 2.Increase in the population of crocodiles in rivers
  3. 3.Getting trapped in fishing nets accidentally
  4. 4.Use of synthetic fertilizers and other agricultural chemicals in crop-fields in the vicinity of rivers

Select the correct answer using the code given below.

a1 and 2 only
b2 and 3 only
c1, 3 and 4 only
d1, 2, 3 and 4

AnswerUPSC’s answer is (c).

The Ganges river dolphin is declining because its habitat is being broken up and degraded. Dams and barrages split populations and reduce flow, accidental entanglement in fishing nets kills many animals, and agricultural chemicals and other pollutants contaminate the river and its prey. A larger population of crocodiles is not recognised as a cause of its decline. So statements 1, 3 and 4 are right.

  • 1. Dams and barrages fragment the river habitat and change flow.
  • 2. An increase in crocodiles is not a recognised cause of the decline.
  • 3. Dolphins are accidentally caught in fishing nets.
  • 4. Agrochemical runoff pollutes the river and harms dolphins and their prey.

How you could have got this

  1. If you were sure statement 2 is not correct, (a), (b) and (d) go: each of them includes 2.

    What you needed to know: An increase in crocodiles is not a recognised cause of the decline.

Only (c) is left. You didn’t need statements 1, 3 or 4.

Which options go is worked out from UPSC’s key and the options, not by a model.

Why each option is right or wrong
  • (a) Wrong. Statement 2 (more crocodiles) is not a recognised reason, and it leaves out statements 3 and 4.
  • (b) Wrong. Statement 2 is not a cause, and it leaves out statements 1 and 4.
  • (c) Right. Dams, accidental netting and agrochemical pollution are all causes.
  • (d) Wrong. Statement 2 is not a cause.

Answer: UPSC’s key. Explanation: written by UPSC Grade, not by UPSC.

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Source: UPSC, Civil Services (Preliminary) Examination 2014, General Studies Paper I, Series A. The paper on upsc.gov.in.