Question

Hemophilia is an x-linked recessive disease. Under which of the following conditions will a female child inherit hemophilia

Answer 1

The conditions in which a female child will inherit the disease of hemophilia, is if both the father and the mother are infected. Another possibility is if the Mother is a carrier for the disease while the Father is the only one affected.

Answer 2

Answer:

The answer is given below:

Explanation:

Hemophilia is a sex-linked recessive disorder. The gene causing hemophilia is present on the X-chromosome. Y-chromosome does not have gene for hemophilia.

During sex determination, a daughter receives an X chromosome from her mother and an X chromosome from her father. A son gets X-chromosome from his mother and Y-chromosome from his father.

If a daughter gets haemophilic gene on X chromosome from her mother and haemophilic gene on X chromosome from her father then a daughter will be haemophilic (XhXh). Thus, in daughter hemophilia will appear only in homozygous condition.

Having heterozygous condition for haemophilic gene (xhX), the daughter is said to be carrier for hemophilia.

The son will be hemophilic if his X-chromosome has hemophilic gene ( XhY) since Y-chromosome deviod of hemeophilic gene.