Comprehension : Comprehension

Q 32 / 466

UPSC CSE Prelims 2025

Passage - It is hard to predict how changes in the climate and the atmosphere's chemistry will affect the prevalence and virulence 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.

With reference to the above passage, the following assumptions have been made:
  1. Global climate change can result in the migration of several plant diseases to new areas.
  2. Scientific understanding of the wild relatives of our present crops would enable us to strengthen food security.
Which of the above assumptions is/are valid?

EXPLANATION

Correct Option (C)

Assumption 1 is valid. The passage states that "changes in the climate and the atmosphere's chemistry will affect the prevalence and virulence agricultural diseases" and that "such changes will make some plant infections more common in all climatic zones." This implies that climate change can facilitate the spread or migration of plant diseases into new geographical regions where they were previously not prevalent.

Assumption 2 is also valid. The passage explains that "centuries of selective breeding have refined the genomes of most high-value crops," resulting in "genetic variations that are not immediately useful to them have been bred out." This makes these crops vulnerable to "changes" and new diseases. The inference is that genetic diversity, often preserved in the wild relatives of crops, is crucial for resilience against evolving threats. Therefore, a scientific understanding of these wild relatives would enable the reintroduction of beneficial genetic traits, thereby enhancing the adaptability and disease resistance of crops and strengthening food security.

Incorrect Options:

Options (A) and (B) are incorrect because they propose that only one of the assumptions is valid, whereas the passage provides clear support for both Assumption 1 and Assumption 2. Option (D) is incorrect as both assumptions are directly inferable from the text provided in the passage.