Question

Given below are two statements.
Statement I - Only males can suffer from haemophilia.
Statement II - The gene for normal clotting of blood in human is recessive.
In the light of above statements, select the correct option given below:

• A. Both statement I and statement II are correct.
• B. Both statement I and statement II are incorrect.
• C. Statement I is correct but statement II is incorrect.
• D. Statement I is incorrect but statement II is correct.

Hint:

Haemophilia is X-linked recessive, so females can also be affected when homozygous, and the normal clotting gene is dominant.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept
Haemophilia is a sex-linked recessive disorder caused by a gene on the X chromosome.

Step 2: Statement I
A female becomes haemophilic only if she is homozygous recessive, for example the daughter of a haemophilic father and a carrier mother.
So it is wrong that only males can suffer.

Step 3: Statement II
The normal allele for blood clotting is dominant and the haemophilia allele is recessive.
So this statement is also wrong.

Final Answer:
Both statements are incorrect. \[ \boxed{\text{(B) }\text{Both statement I and statement II are incorrect.}} \]