UPSC Prelims 2024 · CSAT

Question 53: Reading Comprehension

Passage beginning “Evolution has endowed caterpillars that feed…” — Passage—3 · as printed by UPSC

Which one of the following statements best reflects the most logical, rational and practical message conveyed by the passage?

aFarmers can use caterpillars to feed on weeds in their crop fields/plantations.

bThis finding can help in the development of clinically useful antimicrobial compounds.

cThis finding can help in the development of organic, ecologically sustainable pesticides.

dCaterpillars can be genetically modified to be predators of the other plant pests.

AnswerUPSC’s answer is (c).

The passage reports that caterpillars on corn make the plant lower its defences through a substance in their droppings, and that this could help explain how plants respond to fungal and bacterial infection. The most practical message is that understanding what switches off a plant's defences can lead to better, ecologically sustainable ways of protecting crops, such as organic pesticides. Clinical use, weed control and engineering caterpillars are not supported.

Why each option is right or wrong

(a) Wrong. The caterpillars feed on the crop itself, so they are pests, not weed-eaters.
(b) Wrong. The finding concerns plant response to pathogens; clinical antimicrobial compounds are not mentioned.
(c) Right. Learning how pests switch off plant defences points to sustainable, organic pest control.
(d) Wrong. Genetically modifying caterpillars as predators of pests is not suggested.

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

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Source: UPSC, Civil Services (Preliminary) Examination 2024, General Studies Paper II (CSAT), Series A. The paper on upsc.gov.in.