JAMB - Biology (1990 - No. 35)
Haemophilia results from the mutation of the genes
in the sex chromosome
which control skin colour
which control the mechanism for blood-clotting
which control the formation of haemoglobin
توضیح
Hemophilia is a bleeding disorder where the blood takes much longer to clot than normal. This is because the genes responsible for producing certain clotting factors, like factor VIII (Hemophilia A) or factor IX (Hemophilia B), are mutated. Haemophilia results from mutations in genes on the X chromosome, which are responsible for producing blood clotting factors.