Awoman who has blood type a positive has a daughter who is type o positive and a son who is type b negative. rh positive is a trait that shows simple dominance over rh negativeand 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) a negativeb) o negativec) b positived) ab negativee) impossible to determine

C) B positive is the right answer

Explanation:

Codominance  

ABO blood group is an example of co dominance. According to this  

Two alleles are both dominant,  So A and B are both co dominant, they will express and I allele which will be recessive.  

Type A AA or Ai

Type BBB or Bi

Type AB AB  

Type O ii

Rh antigen is dominant to Rh- (for positive and negative due to presence of Rh antigen  

So for Rh+ = RR (homozygous dominant) and Rr (heterozygous dominant)  

           Rh-= rr (homozygous recessive)

Given conditions in the questions  

Given type                  Alleles for type             Allele for Rh antigen  

Type A Woman A+         Ai                                                Rr

Daughter Type O+          ii                                                 R?

Son type B-                             Bi                                             rr

Father type                          Bi                                           Rr or rr

•As mother is A positive, so definitely the son got his B allele from the father, so father should have allele.  

•So as the daughter is ii, so it means the daughter is getting one i allele from mother and other i allele came from the father  

•As the son have B allele which comes from father, so what is son getting from mother? Definitely he is getting i allele from mother because that the only way mother can donate to the son and not change his blood type.  

•No we know that the son is rr for Rh antigen, which means that he is getting one r from mother because she must have a little r to donate to her son and one r from father

The father is either type B Positive BiRr or type B Negative Birr, but we have no other answer than type B positive in the multiple option. This is the possibility  

there is no

explanation: