136k views
3 votes
If a female carrier for hemophilia and an unaffected male mate, what is the probability the male offspring will have hemophilia?

User ToxaBes
by
7.8k points

1 Answer

6 votes

Final answer:

Male offspring of a female carrier for hemophilia and an unaffected male have a 50% chance of having hemophilia, as the condition is X-linked recessive and males have only one X chromosome.

Step-by-step explanation:

The probability that a male offspring will have hemophilia when the mother is a carrier of the X-linked recessive disorder and the father is unaffected is 50 percent.

This is because females have two X chromosomes and are carriers if only one of the X chromosomes contains the recessive allele for hemophilia. Since males have one X and one Y chromosome, they will develop hemophilia if their single X chromosome carries the recessive allele. The mother will pass on either her normal X chromosome or her X chromosome with the recessive allele. If she passes on the affected X chromosome, the male child will have hemophilia because males have no second X chromosome to counter the recessive allele.

Answer choice 'a' from the options provided, indicating that females need two mutated X chromosomes to be hemophilic, explains why hemophilia is rarer in females. They would have to inherit two affected X chromosomes, one from each parent, which is statistically less likely than a male inheriting a single affected X chromosome from the mother.

Learn more about Hemophilia inheritance

User Makrushin Evgenii
by
9.3k points
Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.