UPSC Prelims 2017 Q78: Science & Technology – Biotechnology & Genetics
What is the application of Somatic Cell Nuclear Transfer Technology?
- (a) Production of biolarvicides
- (b) Manufacture of biodegradable plastics
- (c) Reproductive cloning of animals
- (d) Production of organisms free of diseases
Answer: (c) Reproductive cloning of animals
Explanation
Somatic Cell Nuclear Transfer (SCNT)
In SCNT, the nucleus of a body (somatic) cell is put into an egg cell whose own nucleus has been removed.
The egg then grows into an embryo that is a genetic copy of the donor.
| Step | What happens |
|---|---|
| 1 | Remove the nucleus from an egg cell |
| 2 | Insert the nucleus of a somatic cell from the animal to be copied |
| 3 | Stimulate the egg to divide |
| 4 | Implant the embryo in a surrogate mother |
Famous clones made by this technology:
| Animal | Year | Place |
|---|---|---|
| Dolly the sheep | 1996 | Roslin Institute, Scotland |
| Samrupa, the first cloned buffalo | 2009 | NDRI, Karnal (India) |
It is not used for the production of biolarvicides or the manufacture of biodegradable plastics.
Answer: (c) Reproductive cloning of animals.
Why each option is right or wrong
- (a) Incorrect. Biolarvicides are made from bacteria such as Bacillus thuringiensis.
- (b) Incorrect. Biodegradable plastics are made from starch or microbial polymers.
- (c) CORRECT. SCNT is the technology used for the reproductive cloning of animals.
- (d) Incorrect. A clone copies the donor's genes; it is not automatically free of diseases.
Key point
SCNT: nucleus of a somatic cell placed in an enucleated egg; used for reproductive cloning (Dolly, 1996) and therapeutic cloning.
Remember
Somatic Cell Nuclear Transfer = cloning (Dolly, 1996).
Common mistakes
- Confusing cloning with genetic engineering, which changes genes.
- Thinking a clone is disease-free; it inherits the donor's genetic defects.
- Forgetting that Dolly was cloned from an adult cell, not an embryo cell.
Exam tip
Nuclear transfer = cloning. Remember Dolly the sheep.
Sources
- NCERT Class XII — Biology (Biotechnology and its Applications)
- National Dairy Research Institute, Karnal — Buffalo cloning programme