UPSC Prelims 2025 CSAT Paper II · Q61 of 78 Comprehension medium

Passage

It is hard to predict how changes in the climate and the atmosphere's chemistry will affect the prevalence and virulence of agricultural diseases. But there is a risk that such changes will make some plant infections more common in all climatic zones, perhaps catastrophically so. Part of the problem is that centuries of selective breeding have refined the genomes of most high-value crops. They are spectacular at growing in today's conditions but genetic variations that are not immediately useful to them have been bred out. This is good for yields but bad for coping with changes. A minor disease or even an unknown one could suddenly rampage through a genetically honed crop.

Which one of the following statements best reflects the central idea conveyed by the passage ?

  1. (a) Global climate change adversely affects the productivity of crops.
  2. (b) Our total dependence on genetically honed crops entails possible food insecurity. ✓ UPSC's answer
  3. (c) Our food security should not depend on agricultural productivity alone.
  4. (d) Genetically honed crops should be replaced with their wild varieties in our present cultivation practices.

Why the answer is (b)

• The passage argues that centuries of selective breeding have removed genetic variations from high-value crops to maximize yields under current conditions.

• This genetic uniformity makes crops vulnerable to new or minor diseases, especially as climate and atmospheric chemistry changes.

• The text highlights the risk that such changes could cause plant infections to become more common and potentially catastrophic.

• Therefore, the central idea is that relying entirely on these genetically honed crops creates a significant risk to food security due to their lack of resilience.

Why the other options are wrong

(a) Global climate change adversely affects the productivity of crops.
The passage focuses on the vulnerability of crops to disease due to genetic uniformity, not directly on the adverse effects of climate change on productivity itself.
(c) Our food security should not depend on agricultural productivity alone.
The passage does not suggest diversifying food sources beyond agriculture, but rather warns about the specific risks within agricultural practices due to genetic homogeneity.
(d) Genetically honed crops should be replaced with their wild varieties in our present…
The passage does not advocate for replacing crops with wild varieties, but rather explains why the current reliance on genetically honed crops is risky.

Asked in the CSAT Paper II of the UPSC Civil Services Preliminary Examination 2025, held on 25 May 2025. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.

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