Tom's father has hemophilia, but Tom does not have the disease. What are the chances that Tom's children will have hemophilia?

Question

Quizplus · Accepted Answer

Tom's father has hemophilia, which is a sex-linked recessive trait. This means that the gene for hemophilia is located on the X chromosome. Tom inherited one X chromosome from his father and one X chromosome from his mother. Since Tom does not have hemophilia, he must have inherited the dominant allele for normal blood clotting from his mother. This means that Tom's genotype is X^H Y, where X^H represents the dominant allele for normal blood clotting and Y represents the Y chromosome.Tom's children will inherit one X chromosome from Tom and one X chromosome from their mother. If Tom's children are male, they will inherit the Y chromosome from Tom and will not have hemophilia. If Tom's children are female, they will inherit one X chromosome from Tom and one X chromosome from their mother. If Tom's children inherit the X chromosome with the hemophilia allele from their mother, they will be carriers for hemophilia. However, they will not have hemophilia because they will also inherit the dominant allele for normal blood clotting from Tom.

Tom's Father Has Hemophilia, but Tom Does Not Have the Disease