Biology · Biotechnology and Its Applications · NEET
Before a vaccine is given to humans, its safety must be checked. Transgenic mice are being developed to test whether a vaccine batch is safe. NCERT specifically states transgenic mice are being used to test the safety of the polio vaccine. If they are found reliable, they can replace the use of monkeys for testing vaccine safety.
The polio vaccine. NCERT says transgenic mice are being used to test the safety of the polio vaccine, and if successful they could replace monkeys used to test the safety of vaccine batches. This exact example is a common one-mark question, so remember 'polio vaccine' and 'replace monkeys'.
Toxicity testing, also called chemical safety testing, checks if a substance is harmful. Transgenic animals are made carrying genes that make them MORE sensitive to toxic substances than normal (non-transgenic) animals. They are then exposed to the toxic substance and the effects are studied. This is the same procedure used for testing drug toxicity, and it gives results in less time.
They are two separate NCERT uses. Vaccine safety testing checks whether a vaccine (like polio) is safe before human use and can replace monkeys. Toxicity/chemical safety testing exposes specially made more-sensitive transgenic animals to toxic chemicals or drugs to study harmful effects faster. One is about vaccines, the other is about chemicals and drugs.
Mice breed fast, are small and cheap, have short life cycles, and their genetics are well understood, so they are the easiest animal to modify and study in large numbers. NCERT states that although transgenic rats, rabbits, pigs, sheep, cows and fish exist, over 95 per cent of all existing transgenic animals are mice. This is a frequently tested fact.
Try the real previous-year questions from this chapter — each with the answer and a full solution.
Vaccine safety testing (testing the polio vaccine, can replace monkeys) and chemical safety testing, also called toxicity testing (mice made more sensitive to toxic substances, giving faster results).
Yes. NCERT says if transgenic mice are found successful and reliable for testing the safety of vaccine batches, they could replace the use of monkeys.
No. They are used for safety and toxicity testing and as disease models. Making biological products such as alpha-1-antitrypsin is done by other transgenic animals like sheep and the transgenic cow Rosie.
Because more-sensitive animals react to toxic substances faster and more clearly, which lets researchers obtain results in less time than with normal animals.
Yes. NCERT lists five uses of transgenic animals: normal physiology and development, study of disease, biological products, vaccine safety, and chemical safety (toxicity) testing. This concept covers the last two.
