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 ?
- (a) 1 only
- (b) 2 and 3 only
- (c) 2 only
- (d) 1, 2 and 3 ✓ UPSC's answer
Why the answer is (d)
• Statement 1 is correct: germline editing can alter the cells that produce eggs or sperm, so the change is heritable — technically feasible with CRISPR, though ethically restricted.
• Statement 2 is correct: embryos can be edited at the early stage, as He Jiankui controversially did in 2018 to produce CCR5-edited twins in China.
• Statement 3 is correct: human induced pluripotent stem cells have been injected into pig embryos to create human–pig chimeras for organ research (Salk Institute, 2017).
• All three describe real, if contentious, techniques.
• Hence 1, 2 and 3, option (d).
Why the other options are wrong
- (a) 1 only
- Statements 2 and 3 are also correct.
- (b) 2 and 3 only
- Statement 1 on germline editing is also correct.
- (c) 2 only
- Statements 1 and 3 are also correct.
Asked in the GS Paper I of the UPSC Civil Services Preliminary Examination 2020, held on 4 October 2020. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.