Question

Study the following cross and answer the questions.
[Hint: ABO blood group in man is controlled by three alleles $I^A,I^B$ and i.]
(a) Write the genotypes of the father, mother and son.
(b) The type of dominance of human blood group inheritance is known as

Answer 1

Since the blood group of the son is O, his genotype is i. The genotype of the father with blood group A will be I${}^A$i. The genotype of the mother with blood group B will be I${}^B$i. The type of dominance of human blood group inheritance is co-dominance.

The A and B alleles are codominant. If A is inherited from one parent and B from the other, the phenotype of the child will be AB. This is a co-dominance condition.