UPSC Prelims 2023 CSAT Paper II · Q41 of 77 Comprehension medium

Passage

Directions for the following 3 (three) items : Read the following three passages and answer the items that follow the passages. Your answers to these items should be based on the passages only. Passage – 1 Scientists studied the vernal window — transition period from winter to the growing season. They found that warmer winters with less snow resulted in a longer lag time between spring events and a more protracted vernal window. This change in the spring timetable has ecological, social and economic consequences — for agriculture, fisheries and tourism. As the ice melts earlier, the birds don't return, causing a delay, or lengthening in springtime ecological events.

With reference to the above passage, the following assumptions have been made : 1. Global warming is causing spring to come early and for longer durations. 2. Early spring and longer period of spring is not good for bird populations. Which of the above assumptions is/are correct ?

  1. (a) 1 only ✓ UPSC's answer
  2. (b) 2 only
  3. (c) Both 1 and 2
  4. (d) Neither 1 nor 2

Why the answer is (a)

• The passage states that warmer winters with less snow result in a 'longer lag time' and a 'more protracted vernal window,' which supports the assumption that global warming is causing spring to last for longer durations.

• The text explicitly links warmer winters (a consequence of global warming) to these changes in the spring timetable, validating the causal link in Assumption 1.

• Regarding Assumption 2, the passage notes that as ice melts earlier, birds do not return, causing a delay in ecological events.

• However, the passage does not state that this delay or the lengthening of the vernal window is inherently 'not good' or harmful to bird populations; it only describes the timing mismatch.

• Since the passage does not provide information on the negative impact on bird populations, Assumption 2 cannot be inferred.

• Therefore, only Assumption 1 is correct, making option (a) the right answer.

Why the other options are wrong

(b) 2 only
Assumption 2 is incorrect because the passage does not state that the lengthening of the vernal window is detrimental to bird populations, only that it causes a delay in their return.
(c) Both 1 and 2
This option is incorrect because Assumption 2 is not supported by the passage, which lacks information on the negative impact of the timing change on bird populations.
(d) Neither 1 nor 2
This option is incorrect because Assumption 1 is supported by the passage, which links warmer winters to a more protracted vernal window.

Asked in the CSAT Paper II of the UPSC Civil Services Preliminary Examination 2023, held on 28 May 2023. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.

Reading the answer is not the same as getting it right under a clock. Practise this question with UPSC's negative marking, and anything you miss goes into an error notebook until you get it right twice.

Practise this paper free