In the context of recent advances in human reproductive technology, "Pronuclear Transfer" is used for
Answer & explanation
Answer: (d) prevention of mitochondrial diseases in offspring
Pronuclear transfer is a form of mitochondrial donation, used to stop a mother from passing a serious mitochondrial disease to her child. The nuclear DNA of her fertilised egg is moved into a donor egg that has healthy mitochondria, so the baby gets the parents' genes but the donor's healthy mitochondria.
- ✗ (a) Fertilising an egg in the lab with donor sperm is ordinary IVF. Pronuclear transfer is an extra step done on embryos, not a way of fertilising an egg.
- ✗ (b) The technique does not modify sperm-producing cells or edit genes; it swaps whole nuclear material between embryos.
- ✗ (c) It does not turn stem cells into embryos. It moves the nuclear genetic material of one embryo into another embryo whose own nucleus has been removed.
- ✓ (d) Mitochondrial donation treatment lets people with severe mitochondrial disease avoid passing it to their children. Pronuclear transfer is one of the two approved techniques, the other being maternal spindle transfer.
Remember · Pronuclear transfer = swap the nuclear DNA of an embryo into a donor embryo with healthy mitochondria, to prevent mitochondrial disease.
Sources
- HFEA (UK Human Fertilisation and Embryology Authority), Mitochondrial donation treatment ↗ “Mitochondrial donation treatment can be used by people with severe mitochondrial disease to avoid passing the condition onto their children.”
- Mitochondrial replacement to prevent the transmission of mitochondrial DNA disease (peer-reviewed article on PubMed Central, US National Library of Medicine) ↗ “Regulations were passed to enable the Human Fertilisation and Embryology Authority (HFEA) to consider applications to use pronuclear transfer and spindle transfer in clinical treatment to prevent transmission of mtDNA disease.”
Question and answer: UPSC's official GS Paper I (2020, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). ·