2023 GS Paper I, all questions

UPSC Prelims 2023 · GS Paper I

Question 63: Geography

Consider the following statements :

  1. Statement-IThe soil in tropical rain forests is rich in nutrients.
  2. Statement-IIThe high temperature and moisture of tropical rain forests cause dead organic matter in the soil to decompose quickly.

Which one of the following is correct in respect of the above statements?

aBoth Statement-I and Statement-II are correct and Statement-II is the correct explanation for Statement-I
bBoth Statement-I and Statement-II are correct and Statement-II is not the correct explanation for Statement-I
cStatement-I is correct but Statement-II is incorrect
dStatement-I is incorrect but Statement-II is correct

AnswerUPSC’s answer is (d).

Statement I is wrong: tropical rainforest soils are poor in nutrients. Statement II is correct: heat and moisture make dead organic matter decompose very fast, and the nutrients are quickly taken up by the dense vegetation or washed away by heavy rain (leaching), leaving a thin humus layer and infertile, often laterite, soil. Most nutrients sit in the living biomass, not the soil.

  • I. Rainforest soils are nutrient-poor because of leaching and fast uptake.
  • II. Heat and moisture speed up decomposition.

How you could have got this

If you were sure Statement-I is not correct, only (d) is left: every other option says it is correct.

What you needed to know: Rainforest soils are nutrient-poor because of leaching and fast uptake.

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) Statement I is false, so Statement II cannot explain it.
  • (b) Statement I is false, so 'both correct' fails.
  • (c) Statement I is false; rainforest soils are nutrient-poor.
  • (d) Correct: Statement I is false, Statement II is true.

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

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Source: UPSC, Civil Services (Preliminary) Examination 2023, General Studies Paper I, Series A. The paper on upsc.gov.in.