Give the significance of transgenic animals for betterment of life.

Explanation

Transgenic animal is a fertile animal that carries an introduced gene(s) in its germ line. Transgenic rats, rabbits, pigs, sheep, cows and fish have been produced but more than `95%` of transgenic animals are mice.
Significance of Transgenic Animals :
1. Study of diseases : With the help of these animals investigation of new treatments for human diseases such as cancer, cystic fibrosis, rheumatoid arthritis and Alzheimer's is possible.
2. Vaccine safety : Transgenic animals would also be useful as bioreactors to produce pharmacolo-gically important proteins such as `alpha`-1-anti-trypsin. This is used to treat emphysema. Similar attempts are being made for treatment of phenylketonuria (PKU).
4. Chemical safety testing : Transgenic animals carry genes which make them more sensitive to toxic substances than non-transgenic animals. Toxicity testing in such animals allow to get results in less time.