In: Biology
Hemophilia is a disease caused by a recessive allele on the X chromosome. Use a Punnett square to help describe the offspring phenotypes from the cross: heterozygous female crossed to male with hemophilia.
Hemophilia: It is a rare disorder in which there is a lack of sufficient blood-clotting proteins (clotting factors) which affect the clotting of blood, abnormal clotting of blood. Hemophilia A and hemophilia B are inherited in an X-linked recessive pattern. The gene responsible is present on the X chromosome. If the male have affected mother then there re 100% chance of having he disorder.
Let the allele for the hemophilia disorder is H.
It is a recessive disorder so express only when present on both the chromosomes.
Let,
According to the question the cross between heterozygous female crossed to male with hemophilia.
Cross: XHX * XHY
Punnett square for the cross:
Gametes | XH | X |
XH | XHXH | XHX |
Y | XHY | XY |
Thus, 50% of the offspring has chance of getting the disorder.
XHXH - Affected daughter
XHX - Carrier daughter
XHY - Affected son
XY - Unaffected son
Thank you!