Question

Why is the possibilityof human female become haemophilic extremely rare? explain?

Answer 1

Hemophilia being a sex chromosome related recessive disorder has its gene present on X chromosome. Since males have one X and one Y chromosome, and the genes present on X don't have counter genes on Y, only one affected gene(to be present on X) is required for the disease in males. While in females, there are 2 X chromosomes. For the disease to occur both the X chromosomes should have the affected genes which is a rare chance. For this to be possible, the father of the female must be diseased while the mother must atleast be a carrier.

Answer 2

Answer:

(1) Haemophilia is caused due to X-linked recessive gene. Females have double X chromosomes.

(2) Even if she has haemophilic gene on one of her X-chromosome, the dominant gene on other X-chromosome, suppresses its expression. Female therefore, does not become haemophilic.

13) H she inherits haeriophilic here on both of her X-chromosomes, this combination becomes lethal. Such embryo is aborted. if born, she dies soon. This makes the possibility of female becoming a haemophilic extremely rare.