Reproductive Technology, Stem Cells and Genomics for UPSC: Pronuclear Transfer, Mitochondrial Replacement, Cloning, GenomeIndia and Denisovans

How UPSC Tests Reproductive Technology and Genomics

🎯 Exam priority: Tier-1. Human genetics and reproductive technology produce a steady one or two questions a year. UPSC asked: pronuclear transfer and the prevention of mitochondrial disease (2020); mitochondrial replacement therapy and maternal inheritance (2021); the Denisovans (2019); and, in the 2026 paper, genetic medicine and the GenomeIndia Project. Mains 2017 asked for a short account of stem cell therapy and its advantages.

Three boxes: assisted reproduction (IVF, mitochondrial replacement), cells as medicine (cloning, stem cells, cell and gene therapy) and reading the human genome (GenomeIndia, ancient DNA).

Assisted Reproduction and Mitochondrial Replacement

Assisted reproduction and mitochondrial replacement

• IVF (in vitro fertilisation) fertilises an egg outside the body and transfers the embryo to the uterus. The first 'test-tube baby', Louise Brown, was born in 1978; India's first, Durga, followed in October of the same year.

• Mitochondrial DNA is inherited from the mother only, because the egg supplies the mitochondria. A woman with mutations in her mitochondrial DNA can pass on serious mitochondrial disease, so techniques replace her faulty mitochondria with a donor's healthy ones (2021 PYQ: the statement that the child inherits the disease entirely from the mother is right, and replacement can be done before or after fertilisation).

• Pronuclear transfer is used to prevent mitochondrial disease in offspring (2020 PYQ): the nuclear material of an embryo made from the mother's egg is moved into a donor egg that has had its own nucleus removed. In the related maternal spindle transfer the transfer is done before fertilisation.

• The child carries nuclear DNA from both parents and a small amount of mitochondrial DNA from the donor, hence the media label 'three-parent baby'. In July 2025 the UK's Newcastle team reported eight healthy babies born after its licensed mitochondrial donation treatment; follow-up is short, so it is treated as risk reduction (secondary source).

Cloning, Stem Cells and Genetic Medicine

Cloning and stem cells

• Somatic cell nuclear transfer (SCNT) puts the nucleus of a body cell into an egg whose nucleus has been removed; the egg develops into an embryo that is a genetic copy of the donor. Dolly the sheep (born 1996) was the first mammal cloned from an adult cell.

• Stem cells can renew themselves and turn into specialised cells. Embryonic stem cells are pluripotent; adult (tissue) stem cells, such as those in bone marrow, are more limited; induced pluripotent stem cells (iPSCs) are adult cells reprogrammed to a pluripotent state (Yamanaka, Nobel Prize 2012).

• Stem cell therapy is established for blood disorders such as leukaemia and thalassaemia through bone-marrow transplantation, and for damaged cornea and severe burns by growing tissue from the patient's own cells. Advantages over many treatments are that the cells can replace damaged tissue, there is less rejection when the patient's own cells are used and some conditions have no other cure (Mains 2017).

• Cell and gene therapy: genetic medicines correct or compensate for a faulty gene, and they travel in carriers such as engineered viruses and lipid nanoparticles. They do not rewrite the whole DNA sequence (2026 PYQ, provisional key). India's Department of Biotechnology held a stakeholders' consultation in February 2025 on regulatory pathways for cell and gene therapy products, and 'precision biotherapeutics' is a thematic sector of the BioE3 Policy.

• BIRSA 101, developed by CSIR-IGIB, is India's first indigenous CRISPR-based therapy for sickle cell disease, aimed at affordable gene editing for tribal populations; the technology has been transferred to the Serum Institute of India for low-cost clinical deployment.

• In an Axiom-4 experiment, India's first human muscle stem-cell study on the International Space Station found that muscle regeneration is significantly impaired in microgravity.

Reading the Human Genome and How UPSC Could Ask Next

Reading the human genome

• The Human Genome Project (completed in 2003) sequenced the human genome. GenomeIndia is a separate national project funded by the Department of Biotechnology; its aim is to build a catalogue of the genetic diversity of the Indian population (2026 PYQ, provisional key: it is not part of the Human Genome Project). In January 2025 the Indian Genomic Data Set was unveiled, making 10,000 whole genome samples accessible through the Indian Biological Data Centre, under the Framework for Exchange of Data Protocols (FeED).

• Genomics also helps public health: DBT's TB programme has sequenced about 18,000 Mycobacterium tuberculosis isolates from new patients and found that lineages 2 and 4, though less common in India, carry more multidrug resistance.

• Denisovans (2019 PYQ) were an extinct group of archaic humans known from fossils and DNA in the Denisova cave in Siberia, and traces of their DNA remain in some modern populations, for example in Melanesians. The word does not refer to a dinosaur, a cave system in the North-East or a geological period. The 2022 Nobel Prize in Physiology or Medicine went to Svante Pääbo for sequencing ancient hominin genomes.

How UPSC Could Ask This Next

• Technique-to-purpose pairs: pronuclear transfer, spindle transfer, SCNT, ICSI, iPSC.

• Inheritance: which parent passes on mitochondrial DNA.

• Programmes: GenomeIndia, the Indian Biological Data Centre, BioE3, cell and gene therapy rules.

• Ethics and law: germline editing, surrogacy and ART regulation, consent and data privacy for genomic data.

Further Reading

• NCERT Biology (Class 12) and Geography textbooks, the India State of Forest Report, the MoEFCC Annual Report, the Economic Survey and the official lists cited in this note — the primary sources behind every figure above.

Test Yourself: Practice Questions and PYQs

Twelve practice questions on reproductive technology, stem cells and genomics, followed by the real UPSC Prelims questions and the exact Mains question.

Practice Questions

Q1. Mitochondrial DNA in humans is inherited from

• (a) both parents equally

• (b) the father only

• (c) neither parent

• (d) the mother only

Q2. Pronuclear transfer is used for

• (a) genetic modification of sperm-producing cells

• (b) fertilising an egg in vitro with donor sperm

• (c) prevention of mitochondrial diseases in offspring

• (d) turning stem cells into functional embryos

Q3. Consider the following statements about mitochondrial replacement therapy:
1. It can prevent the transmission of mitochondrial disease from mother to child.
2. The child ends up with some mitochondrial DNA from a donor.
Which of the statements given above is/are correct?

• (a) 2 only

• (b) Neither 1 nor 2

• (c) Both 1 and 2

• (d) 1 only

Q4. Somatic cell nuclear transfer involves

• (a) freezing embryos

• (b) putting the nucleus of a body cell into an egg whose nucleus has been removed

• (c) fusing two sperm cells

• (d) injecting a sperm into an egg

Q5. Induced pluripotent stem cells (iPSCs) are

• (a) stem cells found only in bone marrow

• (b) cells taken only from embryos

• (c) cancer cells grown in culture

• (d) adult cells reprogrammed to a pluripotent state

Q6. Which of the following conditions are treated by stem cell therapy?
1. Leukaemia
2. Thalassaemia
3. Damaged cornea
4. Severe burns

• (a) 3 and 4 only

• (b) 2 and 3 only

• (c) 1 and 2 only

• (d) 1, 2, 3 and 4

Q7. Which of the following statements about the GenomeIndia Project is correct?

• (a) It is a sub-project of the Human Genome Project

• (b) It is funded by the Department of Biotechnology and builds a catalogue of the genetic diversity of the Indian population

• (c) It is run by the Indian Council of Agricultural Research

• (d) It sequences only the genomes of tribal populations

Q8. How many whole-genome samples were made accessible to researchers when the Indian Genomic Data Set was unveiled in January 2025?

• (a) 10,000

• (b) 1 lakh

• (c) 50

• (d) 1,000

Q9. 'Denisovans', sometimes seen in the news, are

• (a) a geological period

• (b) a cave system in North-East India

• (c) an extinct group of archaic humans

• (d) a kind of dinosaur

Q10. Which of the following is true of genetic medicines?
1. They correct or compensate for faulty genes.
2. Engineered viruses and lipid nanoparticles are used as carriers.
3. They alter the entire DNA sequence of the patient.

• (a) 2 and 3 only

• (b) 1 and 2 only

• (c) 1, 2 and 3

• (d) 1 and 3 only

Q11. The first 'test-tube baby' of the world was born in

• (a) 1996

• (b) 1978

• (c) 2003

• (d) 1950

Q12. Muscle regeneration, studied in India's first human muscle stem-cell experiment aboard the International Space Station, was found to be

• (a) unchanged in microgravity

• (b) not measurable

• (c) faster in microgravity

• (d) significantly impaired in microgravity

UPSC Previous Year Questions (PYQs)

Real UPSC Prelims questions, checked against the official paper and answer key.

Q1. (2019) The word 'Denisovan' is sometimes mentioned in media in reference to

• (a) an early human species

• (b) fossils of a kind of dinosaurs

• (c) a cave system found in North-East India

• (d) a geological period in the history of Indian subcontinent

Q2. (2020) In the context of recent advances in human reproductive technology, “Pronuclear Transfer” is used for

• (a) genetic modification of sperm producing cells

• (b) fertilization of egg in vitro by the donor sperm

• (c) prevention of mitochondrial diseases in offspring

• (d) development of stem cells into functional embryos

Q3. (2021) In the context of hereditary diseases, consider the following statements:
1. Passing on mitochondrial diseases from parent to child can be prevented by mitochondrial replacement therapy either before or after in vitro fertilization of egg.
2. A child inherits mitochondrial diseases entirely from mother and not from father.
Which of the statements given above is/are correct?

• (a) 2 only

• (b) 1 only

• (c) Both 1 and 2

• (d) Neither 1 nor 2

Q4. (2026, provisional key) Which of the following statements with regard to genetic medicine is/are correct?
1. Genetic medicines correct/compensate for the faulty genes responsible for disease.
2. Engineered viruses and lipid nanoparticles are used as carriers of the genetic medicine.
3. Genetic medicines alter the entire DNA sequence.
Select the answer using the code given below :

• (a) 1 only

• (b) 1, 2 and 3

• (c) 2 and 3 only

• (d) 1 and 2 only

Q5. (2026, provisional key) Which of the following statements with regard to GenomeIndia Project is/are correct ?
1. It is a part of the Human Genome Project.
2. The project is funded by the Department of Biotechnology (DBT), Government of India.
3. Its primary aim is to build a catalogue of genetic diversity of the Indian population.
Select the answer using the code given below :

• (a) 1, 2 and 3

• (b) 1 and 2 only

• (c) 1 only

• (d) 2 and 3 only

Mains Practice Questions

Use these to frame full-length answers. You don't have to answer one exactly — they show the angles UPSC tests, so let them guide which points you cover.

• Stem cell therapy is gaining popularity in India to treat a wide variety of medical conditions. Describe briefly what stem cell therapy is and what advantages it has over other treatments.

• Explain how mitochondrial replacement works and what the ethical and regulatory issues are.

• What is the significance of the GenomeIndia Project for health care, and what safeguards are needed for genomic data?

• Distinguish between reproductive cloning, therapeutic cloning and stem cell therapy.

• How might cell and gene therapies be made affordable in India?

UPSC Mains — Previous Years’ Questions on this topic (last 10 years)

These are the actual GS Mains questions UPSC has asked on this theme — real proof of how, and when, it is tested. Try to write a full answer to each.

• 2017 (GS-III): Stem cell therapy is gaining popularity in India to treat a wide variety of medical conditions including Leukaemia, Thalassemia, damaged cornea and severe burns. Describe briefly what stem cell therapy is and what advantages it has over other treatments?