Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): Toxicity testing in transgenic animals allows us to obtain results in less time.
Reason (R): The procedure for chemical safety testing in transgenic animals is the same as that used for testing toxicity of drugs.
In the light of the above statements, choose the most appropriate answer from the options given below:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Both (A) and (R) are true but (R) is not the correct explanation of (A).
Assertion (A): Toxicity testing in transgenic animals allows us to obtain results in less time. — True. A is about the speed of chemical safety (toxicity) testing when transgenic animals are used.
Reason (R): The procedure for chemical safety testing in transgenic animals is the same as that used for testing toxicity of drugs. — True. R is about how the test is carried out. The animals are exposed to the toxic substance and the effects are studied, in the same way as drugs are tested.
Why R does not explain A? If the procedure is the same as an ordinary drug test, the procedure itself cannot be what makes the test faster. Results come sooner because the animals carry genes that make them more sensitive to toxic substances than non-transgenic animals, so the effects show up quickly. R describes the method; it does not give the reason for the speed. So both statements are correct, but R is not the explanation of A.
NCERT Extract:
Transgenic Animals – “… (v) Chemical safety testing: This is known as toxicity/safety testing. The procedure is the same as that used for testing toxicity of drugs. Transgenic animals are made that carry genes which make them more sensitive to toxic substances than non-transgenic animals. They are then exposed to the toxic substances and the effects studied. Toxicity testing in such animals will allow us to obtain results in less time.”