Question

There was great excitement around the world when the sheep 'Dolly' was cloned using a nucleus derived from an adult cell of its 'mother' which was then transplanted into an enucleated egg. There is also excitement when it is announced that genes causing human diseases, like muscular dystrophy, have been cloned. Which statement about these two examples of cloning is correct?

• A. They both involve cutting a piece of DNA from the genome.
• B. One involves the cloning of a nucleus and the other is the cloning of a piece of DNA.
• C. They both produce products genetically identical to the original donor of cellular material.
• D. They raise no ethical questions.

Answer 1

The correct option is B One involves the cloning of a nucleus and the other is the cloning of a piece of DNA.

The sheep 'Dolly' was produced by transferring either nucleus into an enucleated cell while cloning of genes like genes of muscular dystrophy involves cutting the DNA piece containing the particular gene and transferring it through a vector or through other methods into a host cell. Tools of recombinant DNA technology like restriction enzymes, etc., are not used in first experiment while they are essential for the second. In first experiment, cells express all the genes of the donor while cells in the second experiment, express only the desirable gene that is transferred.