A baby has blood type B, Rh+, and the mom has blood type O, Rh-. Is it possible for a man of blood type AB, Rh- to be the father?

Expert Answers
jerichorayel eNotes educator| Certified Educator

To solve for the answer to this problem, we should first show the genotypes of the blood type of the parents.

Parent 1: O, genotype OO

Parent 2: AB, genotype AB

Now to see to see the possible phenotypes of the offspring, we will do the punnett square:

      O    O

A   AO  AO

B   BO  BO

The baby has a blood type of B (genotype: BB or BO). Therefore the baby can have a blood type of B. But we still have to determine the Rh factor of the baby to know the answer.

Rh+ = genotype: Rh+/Rh+ or Rh+/Rh-

Rh- = genotype: Rh-/Rh-

Since both the parents are Rh-, their baby cannot be Rh+ which is indicated in the problem. 

Therefore, it is not possible for a man of blood type AB, Rh- to be the father. 

daiwa | Student
Mother's group O Father's group AB Mother's Rh Rh- Father's Rh Rh- For the above information The Child will be A or B, Rh-

In this case, The baby cannot be having Rh+ blood group..