133k views
5 votes
Hemophilia is an X-linked recessive allele causing a blood disorder. What are the chances that a daughter of a normal man and a woman, who is heterozygous for the disease, will have hemophilia?

User TLadd
by
7.8k points

1 Answer

1 vote

Final answer:

The chance of a daughter having hemophilia from a normal father and a heterozygous mother is 0%, but there's a 50% chance that she will be a carrier of the disorder.

Step-by-step explanation:

Hemophilia is an X-linked recessive trait that results in a deficiency of clotting factors, leading to a blood disorder. To determine the chances that a daughter of a normal man and a heterozygous woman will have hemophilia, we need to analyze the genetic possibilities. The man, having a normal Y chromosome (XY) will always pass on his normal X chromosome to his daughters, while the woman, with one normal and one affected X chromosome (XH Xh), has a 50% chance of passing on the affected gene.

Since the daughter receives one X from her father and one X from her mother, there are two possibilities:
Normal X from mother (XH): The daughter will not have hemophilia but will be unaffected since she has one normal X from her father and a normal X from her mother.

Affected X from mother (Xh): The daughter will also be unaffected but will be a carrier of the trait due to the normal X from her father balancing the affected X from her mother.

Therefore, the chance that the daughter will have hemophilia is 0%, but the chance that she will be a carrier like her mother is 50%.

User Sangarllo
by
7.2k points