What type of inheritance pattern explains the blood type of a child with blood type AB, born to a father with blood type B and a mother with blood type A?

The inheritance pattern that explains the blood type of a child with blood type AB, born to a father with blood type B and a mother with blood type A, is codominance. In this scenario, both parents contribute allele variations that are equally expressed in the phenotype of the offspring.

In the ABO blood group system, there are three alleles: A, B, and O. The A and B alleles are codominant with respect to each other, meaning that when both are present, they manifest independently in the individual's blood type. The mother can pass on an A allele and the father can pass on a B allele to their child. As a result, the child expresses both A and B antigens on the surface of their red blood cells, leading to a blood type of AB.

The concept of codominance is crucial here because it illustrates how different alleles can be simultaneously expressed in a heterozygous individual without one overpowering the other. In this case, the presence of both the A and B alleles creates the AB blood type, a direct demonstration of codominance in action.

Other inheritance patterns do not apply to this situation: incomplete dominance would result in a blended phenotype, while autosomal recessive