UPSC Prelims 2016— Question 34

This question from the 2016 Civil Services Preliminary Examination tests Science & Technology through the specific theme of Biology, particularly Viruses and Host Organisms. The key point tested here is the relationship between the question's subject and Viruses and Host Organisms. The correct choice is D. In UPSC Prelims, the safest approach is to test each statement or option against the precise institutional, historical, geographical, scientific or economic definition involved rather than relying on a familiar-sounding phrase. The distinction is important because several distractors are constructed by attaching a broadly related fact to the wrong institution, scheme, location, period, mechanism or objective. The question should therefore be solved by identifying the exact proposition that the examination is asking the candidate to validate, and then eliminating statements that overstate, misidentify or alter the scope of the proposition. Option A: 1 and 2 only. This is not the correct option. It either excludes a statement that is valid, includes a statement that is incorrect, or gives a description that does not match the precise subject asked in the question. UPSC distractors often use closely associated terms, institutions or facts, so the candidate must distinguish the exact scope rather than treating partial similarity as sufficient. Option B: 3 only. This is not the correct option. It either excludes a statement that is valid, includes a statement that is incorrect, or gives a description that does not match the precise subject asked in the question. UPSC distractors often use closely associated terms, institutions or facts, so the candidate must distinguish the exact scope rather than treating partial similarity as sufficient. Option C: 1 and 3 only. This is not the correct option. It either excludes a statement that is valid, includes a statement that is incorrect, or gives a description that does not match the precise subject asked in the question. UPSC distractors often use closely associated terms, institutions or facts, so the candidate must distinguish the exact scope rather than treating partial similarity as sufficient. Option D: 1, 2 and 3. This is the correct option. It matches the verified answer and represents the combination or proposition that satisfies the conditions given in the question. Where the question contains multiple statements, the correctness of this option follows from accepting only those statements that accurately describe the relevant concept. Prelims takeaway: remember the precise association between Viruses and Host Organisms and the underlying Science & Technology concept. For statement-based questions, evaluate every statement independently before looking at the combination codes. This prevents a candidate from selecting an option merely because one part appears familiar. The verified answer for this question is Option D.