Gene H determines normal blood clotting in humans, and gene n determines hemophilia.

Gene H determines normal blood clotting in humans, and gene n determines hemophilia. A woman who is heterozygous for the hemophilia gene married a man with normal blood clotting. determine the phenotype and genotype of children who may be born from such a marriage.

Let’s designate the chromosome with which the gene responsible for the development of hemophilia is linked as “Xh”, then the chromosome responsible for the development of the normal blood coagulation system will be “XH”. The Y-chromosome, as you know, does not carry information about the blood coagulation system.

A woman who does not suffer from hemophilia, but, according to the condition of the problem, is heterozygous for this disease – XHXh, she will produce eggs Xh and XH.

A man with normal blood clotting XHY, he produces XH and Y sperm.

Variants of the offspring of such a pair:

healthy girls XHXH and XHXh – 50%;

boys with hemophilia XhY – 25%;

healthy boys XHY – 25%.