Correct answer: (d) 1, 2 and 3
Explanation
- A
1 only
1 only. Embryonic editing and pig-embryo iPSC chimeras were also already shown in labs.
- B
2 and 3 only
2 and 3 only. Germ-line (egg/sperm) editing is also possible in principle/practice as keyed.
- C
2 only
2 only. Under-counts.
- D
1, 2 and 3
All three. Germ-line edits, early-embryo genome editing, and human iPSCs into a pig embryo — all reported as technically done.
Summary. Official key is (d) 1, 2 and 3. By 2020, labs could edit prospective parents’ germ cells, edit early human embryos, and inject human iPSCs into pig embryos. All three statements hold as capability claims.
Same topic · past papers
UPSC has asked this before
These previous-year questions sit on the same topic. Open one to practise the earlier ask.