EVERYDAY SCIENCE

Detailed explanation-1: -Thus, males can have a disease like hemophilia if they inherit an affected X chromosome that has a mutation in either the factor VIII or factor IX gene. Females can also have hemophilia, but this is much rarer. In such cases both X chromosomes are affected or one is affected and the other is missing or inactive.

Detailed explanation-2: -Hemophilia is an inherited bleeding disorder primarily affecting males-but females can also have hemophilia.

Detailed explanation-3: -These disorders affect males more often than females because females have an additional X chromosome that acts as a “back-up.” Because males only have one X chromosome, any mutation in the factor VIII or IX gene will result in hemophilia. Females with a mutation on one X chromosome are called “carriers”.

Detailed explanation-4: -There are no genes for clotting factors on the Y chromosome. This means that males only have one allele for factor VIII and one allele for factor IX. Thus, if a male has a hemophilia allele on his only X chromosome, he will have the disorder.

Detailed explanation-5: -The mother is the one who passes the hemophilia gene. However, it is the father’s sperm that determines if the child will be a boy or a girl. It is not the “fault” of one parent since both parents contribute to the outcome.