Question

Mrs. Smith has blood type A. Her father has blood type A, and her mother has blood type B. If Mr. Smith has blood type AB, what is the probability that they will have a child with blood type AB?
a-25%
b- 50%
c-100%
d-0%

Answer 1

The answer would be A. 25%

Answer 2

Answer: The correct answer is-

a-25%

ABO blood group shows multiple allelism that is has more than two alleles. AB alleles show co-dominance and O allele is recessive allele.

As per the information in the question, Mrs. Smith has blood type A, her father has blood type A ( genotype could be AA/AO), and her mother has blood type B ( genotype would be BO only). This means that she has inherited A allele from her father and O allele from her mother to make the blood type A. Thus, genotype of Mrs. Smith would be AO.

Mr. Smith has blood type AB ( that is genotype would be AB).

So, the genotypes of these parents would be-

Mrs. Smith- AO

Mr. Smith- AB

When these parents are crossed, they will have 25% probability of having child with blood type AB.