Since Dolly the sheep, many other mammals have also been cloned by somatic cell nuclear transfer. The genetic material from a body cell is inserted into an egg cell that has had its own nucleus removed. The success rate ranges from 0.1% to 3%, which is why so few cloned animals have been produced.
Which of the following are possible correct reasons why cloning may fail?
- An egg with a newly transferred nucleus may not begin to divide or develop properly.
- The sperm cell may not fertilise the egg cell.
- Implantation of the embryo into the surrogate mother might fail.
- Implanted stem cells may not differentiate properly.
- The enucleated egg and the transferred nucleus may not be compatible.
Answer:
17) A
1 – Correct
If the off does not divide then the organism cannot form.
2 – Wrong
There is no use of sperm cells
3 – Correct
If the implantation fails, then the cloning will obviously fail
4 – Wrong
The egg must divide and not differentiate
5 – Correct
If the enucleated egg and the transferred nucleus are not compatible, then the cloning will not take place
Statements 1, 3 and 5 are correct so A is the answer.
