UPSC Prelims 2020 · GS Paper I
Question 44: Science and Technology
Consider the following statements :
- 1.Genetic changes can be introduced in the cells that produce eggs or sperms of a prospective parent.
- 2.A person’s genome can be edited before birth at the early embryonic stage.
- 3.Human induced pluripotent stem cells can be injected into the embryo of a pig.
Which of the statements given above is/are correct ?
AnswerUPSC’s answer is (d).
Germline editing alters eggs or sperm, or the cells producing them, so changes pass to children. A person's genome can be edited at the early embryonic stage, as shown by the 2018 gene-edited babies case in China. Human induced pluripotent stem cells have been injected into pig embryos to produce human-pig chimeras. All three statements are correct.
- 1. Germline cells can be genetically changed.
- 2. Embryonic genome editing has been done.
- 3. Human stem cells have been injected into pig embryos to make chimeras.
How you could have got this
- If you were sure statement 1 is correct, (b) and (c) go: each of them leaves 1 out.
What you needed to know: Germline cells can be genetically changed.
- Then, if you were sure statement 2 is correct, (a) goes: it leaves 2 out.
What you needed to know: Embryonic genome editing has been done.
Only (d) is left. You didn’t need statement 3.
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: statements 2 and 3 are also correct.
- (b) Wrong: statement 1 is also correct.
- (c) Wrong: statements 1 and 3 are also correct.
- (d) Right: all three are correct.
Answer: UPSC’s key. Explanation: written by UPSC Grade, not by UPSC.
Source: UPSC, Civil Services (Preliminary) Examination 2020, General Studies Paper I, Series A. The paper on upsc.gov.in.