AP BIOLOGY

Detailed explanation-1: -A woman who is a carrier has: a 25% (one in four) chance of having a daughter who is a carrier. a 25% chance of having a son with hemophilia. and a 50% chance of having a child (boy or girl) who does not have the gene for hemophilia at all (Figure 2.5)

Detailed explanation-2: -So, the correct answer is ‘50% sons will have haemophilia’.

Detailed explanation-3: -If a mother is heterozygous (a carrier) for hemophilia and the father does not have hemophilia, each son has a 1 in 2 (50%) chance of getting his mother’s hemophilia allele and having hemophilia. Each daughter has a 1 in 2 (50%) chance of getting her mother’s hemophilia allele and being heterozygous.

Detailed explanation-4: -As shown in the above diagram, the female offspring will not have hemophilia. However, there is a 50% chance that a female will be a carrier of the disorder. For a male offspring, there is a 50% chance that he will not inherit the disorder and a 50% that he will have hemophilia.

Detailed explanation-5: -If the mother has one altered factor gene and the father does not have hemophilia, each son has a 50% chance of having hemophilia and each daughter has a 50% chance of having one altered factor gene, causing her to be a carrier or have hemophilia.