Question

Haemophilic man marries a normal woman. Their offsprings will be

• A. all haemophilic
• B. all boys haemophilic
• C. all girls haemophilic
• D. all normal.

Answer 1

The Correct Option is D

To determine the genetic outcome when a haemophilic man marries a normal woman, we need to understand some basic genetics related to sex-linked inheritance, as haemophilia is an X-linked recessive disorder. 

Understanding Haemophilia

Haemophilia is a genetic disorder usually linked to the X chromosome. It is mostly expressed in males and inherited from their mothers, who are carriers. For females to exhibit haemophilia, they must inherit the faulty gene from both parents.

Genetic Representation

• The genotype of a haemophilic man is \(X^hY\) where \(X^h\) is the haemophilic gene on the X chromosome.
• The genotype of a normal (non-carrier) woman is \(XX\) where neither X chromosome carries the haemophilia gene.

Offspring Analysis

The potential gametes from each parent and their combinations can be represented as follows:

Father's Gametes	Mother's Gametes	Offspring Genotype	Phenotype
Xh	X	XhX	Carrier Female (Normal)
Y	X	XY	Normal Male

From the table, we can conclude:

• 50% of the offspring will be carrier females (X^hX) who are normal in phenotype.
• 50% of the offspring will be normal males (XY).

Since none of the offspring are haemophilic in phenotype, the correct answer is all normal.

Conclusion

When a haemophilic man marries a normal woman, all their children will be phenotypically normal, but female children will be carriers of the haemophilia gene.