Question

Assertion (A): A male individual always inherits haemophilia from his mother.
Reason (R): The gene for haemophilia lies on X-chromosome.

• 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 \textit{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:

X-linked recessive traits like haemophilia are inherited by sons from carrier mothers.

Answer 1

The Correct Option is A

Haemophilia is an X-linked recessive disorder. A male (XY) receives his single X chromosome from his mother. If this X carries the defective haemophilia gene, he will express the disorder. Hence, both Assertion and Reason are true and Reason explains the Assertion.