Genetics Question! Which of the following is a possible phenotype for the father? genotype for the mother?

Question

A woman who has blood type A has a daughter who is type O and a son who is type B-. Rh is a trait that shows simple dominance over Rh- and is designated by the alleles R and r, respectively. A third gene for the MN blood group has codominant alleles M and N.

Which of the following is a possible phenotype for the father?

A) impossible to determine B) A- C) B D) O- E) AB

Which of the following is a possible genotype for the mother?

A) I(BIB) B) ii C) I(Ai) D) I(AIB) E) I(AIA)

anything in parenthesis are superscript for the above answer choices.

Answer 1

Only C for the answers to both.

For the mom to have blood type A, she has to have at least one A allele.  Since she has a daughter who it O, the daughter has to have received an O (or rather i) from both the mom and the dad.  Since they have a son who is B, that must have come from the dad.  So the genotype of all 4 members can be deduced:

Mom is AO  or Ai

Dad is BO or Bi

daughter is OO or ii

son is BO or Bi