What are the predicted phenotypes of the male children from the union of a woman who is heterozygous for hemophilia and a man who has normal blood clotting characteristics? (Use the Punnett square to verify your answer.)
A) All male children will be healthy.
B) 3 healthy:1 hemophilia
C) 1 hemophilia:1 healthy
D) 1 hemophilia:3 healthy
E) All male children will have hemophilia.

Question

Quizplus · Accepted Answer

Hemophilia is a sex-linked recessive trait. The mother, being heterozygous, carries one allele for hemophilia (X^h) and one normal allele (X^H). The father, with normal blood clotting, has only the normal allele on his X chromosome (X^H) and a Y chromosome. When they have male children, the sons receive their X chromosome from their mother and their Y chromosome from their father. Therefore, there is a 50% chance (1:1 ratio) that a male child will inherit the X^h chromosome from the mother and have hemophilia, and a 50% chance he will inherit the X^H chromosome and be healthy.

What Are the Predicted Phenotypes of the Male Children from the Union