UPSC Prelims 2018 · GS Paper I
Question 87: Environment and Ecology
Consider the following statements :
- 1.Most of the world’s coral reefs are in tropical waters.
- 2.More than one-third of the world’s coral reefs are located in the territories of Australia, Indonesia and Philippines.
- 3.Coral reefs host far more number of animal phyla than those hosted by tropical rainforests.
Which of the statements given above is/are correct ?
AnswerUPSC’s answer is (d).
Most reef-building corals grow in warm, shallow tropical waters. Australia, Indonesia and the Philippines together hold more than a third of the world's coral reefs. Coral reefs also host a greater number of animal phyla than tropical rainforests do. All three statements are correct. Remember: reefs are the marine counterpart of rainforests in richness of life, and in phyla they exceed them.
- 1. Reefs are mostly tropical.
- 2. Australia, Indonesia and the Philippines hold over a third.
- 3. Reefs host more animal phyla than rainforests.
How you could have got this
- If you were sure statement 2 is correct, (b) and (c) go: each of them leaves 2 out.
What you needed to know: Australia, Indonesia and the Philippines hold over a third.
- Then, if you were sure statement 3 is correct, (a) goes: it leaves 3 out.
What you needed to know: Reefs host more animal phyla than rainforests.
Only (d) is left. You didn’t need statement 1.
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) Incomplete: statement 3 is also correct.
- (b) Incomplete: statements 1 and 2 are also correct.
- (c) Incomplete: statement 2 is also correct.
- (d) Right: all three.
Answer: UPSC’s key. Explanation: written by UPSC Grade, not by UPSC.
Source: UPSC, Civil Services (Preliminary) Examination 2018, General Studies Paper I, Series A. The paper on upsc.gov.in.