UPSC Prelims 1999 · General Studies

Question 130: Science and Technology

Assertion (A): Dolly was the first cloned mammal. Reason (R): Dolly was produced by in-vitro fertilization.

aBoth A and R are true, and R is the correct explanation of A

bBoth A and R are true, but R is not a correct explanation of A

cA is true, but R is false

dA is false, but R is true

AnswerThe answer is (c).

Dolly the sheep (born 1996, announced 1997) was the first mammal cloned from an adult cell, so A is true as the question treats it. R is false: Dolly was produced by somatic cell nuclear transfer, in which the nucleus of an udder cell was put into an egg cell whose own nucleus had been removed. In-vitro fertilisation joins an egg and a sperm, which did not happen. Remember: Dolly means nuclear transfer, not IVF.

A. Dolly is treated as the first cloned mammal.
R. Dolly was produced by nuclear transfer, not in-vitro fertilisation.

How you could have got this

If you were sure statement 1 is correct, (d) goes. Then judge the second statement; if it is correct too, decide whether it explains the first.

This follows an unofficial answer: UPSC has not published its key for this year, and if that answer is wrong, so is this path.

Which options go is worked out from UPSC’s key and the options, not by a model.

Why each option is right or wrong

(a) Wrong. R is false: IVF was not used.
(b) Wrong. R is false.
(c) Right. A is true; R is false because Dolly came from nuclear transfer.
(d) Wrong. A is true.

Explanation: written by UPSC Grade, not by UPSC.

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Source: UPSC, Civil Services (Preliminary) Examination 1999, General Studies. UPSC's own paper isn't online; the words are from a published compilation. The paper on upsc.gov.in.