Question

Hemophilia is a sex-linked recessive disorder. If a female is a carrier for hemophilia and is married to a man with hemophilia, what is the probability that she will have a daughter with hemophilia?

A. 50% of the daughters will have hemophilia and 50% of the daughters will be non-carriers.

B.100% of the daughters will have hemophilia.

C. 50% of the daughters will have hemophilia and 50% of the daughters will be carriers for the trait.

D. 100% of the daughters will be non-carriers.

Answer 1

PICTURE IT LIKE THIS... XX- IS FEMALE   XY- IS MALE  AA-NO HEMOPHILIA

Aa-CARRIER   aa- HEMOPHILIA

         X A                                            Xa-(hemophilia trait)

 Xa   XAXa -FEMALE;CARRIER            XaXa - FEMALE;HEMOPHILIA

  Y    XAY -MALE;NO HEMOPHILIA     XaY-MALE;HEMOPHILIA

SO..... 1/4 =FEMALE HEMOPHILIA  1/4=FEMALE CARRIER

          1/4=MALE HEMOPHILIA  1/4= MALE NON-HEMOPHILIA

BUT SINCE WE ARENT LOOKIMG AT BOYS IT WILL BE ....

50%  DAUGHTERS WITH HEMOPHILIA AND 50% DAUGHTERS AS CARRIERS

THE ANSWER IS C !