(a) What are transgenic animals ?
Name the transgenic animal having the largest number amongst all the existing transgenic animals.(c) Mention any three purposes for which these animals are produced.

Explanation

(a) Animals that have had their DNA manipulated to possess and express an extra gene are known as transgenic animals.
(b) 95% of all existing transgenic animals are mice.
(c) Three purposes for which these animals are produced :
(i) Normal physiology and development : Transgenic animals can be secially designed to allow the study of how genes are regulated, and how they affect the normal functions of the body and its development.
(iii) Vaccines safety : Transgenic mice are being developed for use in testing the safety of vaccines before they are used on humans.