Question

Given below are two statements: one is labelled as
Assertion (A) and the other is labelled as Reason (R).
Assertion (A): Inbreeding increases the homozygosity of allele at a locus. Reason (R): High homozygosity enhances genetic load. In the light of the above statements, choose the most appropriate answer from the options given below :

• A. Both (A) and (R) are correct and (R) is the correct explanation of (A)
• B. Both (A) and (R) are correct but (R) is not the correct explanation of (A)
• C. (A) is correct but (R) is not correct
• D. (A) is not correct but (R) is correct

Hint:

Inbreeding increases homozygosity, which may expose harmful recessive alleles and increase genetic load in a population.

Answer 1

The Correct Option is B

Concept: In population genetics, inbreeding refers to: \[ \text{Mating between genetically related individuals} \] Inbreeding has important genetic consequences such as:
• Increase in homozygosity,
• Reduction in heterozygosity,
• Expression of recessive alleles,
• Rise in genetic disorders.

Step 1: Analyzing Assertion (A). Assertion states: \[ \text{Inbreeding increases homozygosity at a locus} \] This statement is scientifically correct because related individuals are more likely to carry:
• Similar alleles,
• Common ancestral genes. As a result: \[ \text{Probability of identical alleles pairing increases} \] Therefore: \[ \text{Homozygosity increases} \] Thus: \[ \boxed{\text{Assertion (A) is correct}} \]

Step 2: Analyzing Reason (R). Reason states: \[ \text{High homozygosity enhances genetic load} \] This statement is also correct because:
• Harmful recessive genes become expressed,
• Genetic disorders increase,
• Fitness may decrease. This phenomenon is called: \[ Inbreeding depression \] Hence: \[ \boxed{\text{Reason (R) is correct}} \]

Step 3: Checking whether Reason explains Assertion. The assertion explains: \[ \text{Effect of inbreeding on genotype frequency} \] The reason explains: \[ \text{Consequence of increased homozygosity} \] Thus, Reason (R) does not explain why inbreeding increases homozygosity. Instead, it describes one outcome of increased homozygosity. Therefore: \[ \boxed{\text{Reason is not the correct explanation of Assertion}} \]

Step 4: Final conclusion. Both statements are correct, but Reason does not correctly explain Assertion. Hence, the correct answer is: \[ \boxed{\text{(B) Both (A) and (R) are correct but (R) is not the correct explanation of (A)}} \]