Blood typing in humans depends on three alleles. The A and B alleles are codominant, and the O allele is recessive. An AB blood type mother has children with a B blood type father (genotype BO). What are the chances that their children will have AB type blood?

25%

Explanation:

If a mother of blood type AB has children with father of blood type BO than there is a 25% chance that they had a child with blood type AB.

As the mother has two alleles A and B.

Father has two alleles B and O. So there are total of 4 sequences AB, AO, B, and BO.

AB 25%

AO 25%

B 25%

BO 25%

that's all i luck!