Hemophilia is an X-linked recessive phenotype. Suppose a man who expresses the hemophilia phenotype has children with a woman who has the normal phenotype (and does not have a family history of hemophilia). If the couple have a son, what are the chances that he will have hemophilia? A) 50% B) 25% C) 0% D) 100%
Hemophilia is an X-linked recessive
A) 50%
B) 25%
C) 0%
D) 100%
Hemophilia is an X linked recessive bleeding disorder in which blood doesn't clot normally.
Females have two copies of X chromosome, and the disease is X linked recessive ,it will not express in heterozygous state in females so, they become carriers with normal phenotype if have one Xh.
Males have only copy of X chromosome ,that's why they are affected even after receiving one Xh from the carrier mother.
According to the question : The man is affected having genotype XhY .
The woman is normal with no family history of hemophilia ,it means she is not a carrier for the hemophilia gene. So, here genotype would be XX.
Now, let's cross the hemophiliac man and the normal woman to get genotypes of their children.
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