Question

daughters born to a hemophiliac father and non - hemophiliac homozygous mother
a are carriers of the disease
b cannot be carriers of the disease
c will definitely have hemophilia
d none of the above

Explanation:

Hemophilia is an X - linked recessive disorder. Let \(X^h\) represent the hemophilia - carrying X chromosome and \(X^H\) represent the normal X chromosome. The father is hemophiliac, so his genotype is \(X^hY\). The mother is non - hemophiliac homozygous, so her genotype is \(X^HX^H\).
When they have children:

• The father can pass either \(X^h\) or \(Y\) to the offspring.
• The mother can only pass \(X^H\).

For daughters:

• They will receive \(X^H\) from the mother and \(X^h\) from the father.
• The genotype of daughters is \(X^HX^h\).

Answer:

A. Are carriers of the disease