Question

Assertion (A) : Hardy-Weinberg principle says that allele frequencies in a population are stable.

Reason (R) : Hardy-Weinberg principle is applicable only when genetic drift does not occur.

• A. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
• B. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
• C. Assertion (A) is true, but Reason (R) is false.
• D. Assertion (A) is false, but Reason (R) is true.

Hint:

The principle needs the absence of all five disturbing factors (gene flow, drift, mutation, recombination, selection), not drift alone.

Answer 1

The Correct Option is C

Step 1: Check the Assertion
The Hardy-Weinberg principle says that allele frequencies in a population stay constant from generation to generation. So (A) is true.

Step 2: Check the Reason
The principle holds only when all the evolutionary factors are absent: no gene flow, no genetic drift, no mutation, no genetic recombination and no natural selection. The reason names only genetic drift, so as a condition it is not correct. It is treated as false in the official scheme.

Step 3: Choose the option
A is true and R is false, which is option (C).

Final Answer:
Option (C): Assertion (A) is true, but Reason (R) is false.