Answer to Question #127617 in Genetics for rabiya zaheer

Question

A woman with type A blood has parents who are both type AB and a husband who is a type B. What is the probability that their first child will be a son with type O blood?explain its mechanism

Answer 1

Blood type inheritance is likened to inheritance of eye or even hair color for instance. Each of us have two of the ABO blood type alleles due inheritance of a single allele from each of our biological parents. A and B alleles are dominant while the O alleles are recessive.

AB blood type parents can either pass A or B alleles to their offspring, with a possibility of the offspring being blood type A, AB and B, with AA, AB and BB possible genotypes so that the woman's possible genotype would be AA but of blood type A. The man's blood type B can either have BB or BO as the possible genotypes. So arguably, since inheritance is a 'one allele one parent rule', a blood type A (genotype AA) woman with a blood type B (genotype BB) man can only possibly have AB blood type children. However, A blood type woman (genotype AA) and a B blood type man (genotype BO) can possibly have AB and A blood type children. So that after considering the two possible genotypes of the father, there is still no evidence of possibly having a blood type O son for the two parents in the question since O alleles are recessive. Numerically represented, the probability of their first child being a boy with blood type O is 0.