Question

Why are transgenic animals produced? Highlight the reasons.

Answer 1

Step 1: Understanding the Concept:
Transgenic animals are animals that have had their DNA manipulated to possess and express an additional (foreign) gene, and they are produced for several important reasons.

Step 2: Reason 1 — Studying Normal Physiology and Development:
Transgenic animals allow scientists to study how genes are regulated and how they affect the normal functions of the body and its development.

Step 3: Reason 2 — Study of Disease:
Many transgenic animals are specially designed to serve as models for human diseases, such as cancer, cystic fibrosis, and rheumatoid arthritis, allowing researchers to study disease progression and test potential new treatments.

Step 4: Reason 3 — Production of Biological Products:
Transgenic sheep and cows have been engineered to produce useful biological products (such as the human protein alpha-1-antitrypsin, used to treat emphysema) in their milk.

Step 5: Reason 4 — Vaccine and Chemical Safety Testing:
Transgenic mice are being developed to test the safety of vaccines (e.g. polio vaccine) before they are used on human beings, and transgenic animals can also be used to detect the toxicity of new chemical substances more quickly than testing on normal animals.

Final Answer:
\(\text{Transgenic animals are produced to study gene function, model human diseases, manufacture biological products, and test vaccine/chemical safety}\)