(a) Why are transgenic animals being produced?

The animals whose genome has been modified to carry and express a foreign gene (gene of other organisms) are called transgenic animals. Examples include transgenic mice, rats, pigs, cows etc. that have been modified to carry a transgene.

Transgenic animals are being produced for various purposes:

• For research purposes such as to study the effect of a drug, its toxicity and side effects and to evaluate the efficacy of vaccines.
• To produce a better yield of products obtained from animals as well as their nutritional enrichment such as milk.
• To produce good quality breeds.
• To develop a disease model and study the mechanism and prognosis of a disease.