Transgenic animals have various applications, and they can be utilized to:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → All of these
Transgenic animals are animals whose DNA has been changed so that they carry and express an extra (foreign) gene. Over 95 per cent of them are mice. They are made for several uses: to study normal physiology and development, to study disease, to make biological products, to test vaccine safety and to test chemical safety.
Option (1) Investigate normal physiology — Correct statement, but it is only one of the correct points, so on its own it is not the answer. Transgenic animals help to study how genes are regulated and how they affect normal body functions and development, for example the role of insulin-like growth factor.
Option (2) Examine vaccine safety — Correct statement, but it is only one of the correct points, so on its own it is not the answer. Transgenic mice are used to test the safety of vaccines, such as the polio vaccine, before they are used on humans.
Option (3) Generate biological products — Correct statement, but it is only one of the correct points, so on its own it is not the answer. Transgenic animals can make useful biological products, such as human α-1-antitrypsin for emphysema, or the human protein-enriched milk of the cow Rosie.
NCERT Extract:
Transgenic Animals – “… (i) Normal physiology and development: Transgenic animals can be specifically designed to allow the study of how genes are regulated, and how they affect the normal functions of the body and its development, e.g., study of complex factors involved in growth such as insulin-like growth factor. … (iii) Biological products: Medicines required to treat certain human diseases can contain biological products, but such products are often expensive to make. … (iv) Vaccine safety: Transgenic mice are being developed for use in testing the safety of vaccines before they are used on humans.”