Answer:
Could this man be the father of the child? Yes.
Possible crosses:
Man: AB
Woman: AA --> Child: AB
Woman: AO --> Child: B
Assuming that he is the father, the mother's genotype must be AO.
Step-by-step explanation:
Yes, it is possible that the man with AB blood is the father of the child who is type B. This is because type B blood can be produced from a combination of type A and type B alleles. The man's blood type, AB, is a result of having both type A and type B alleles.
If the man is the father, the mother's genotype must be AO (having one A allele and one O allele). This means that she is a carrier of both type A and type O blood and can pass either type A or type O to her child. The child's blood type, B, can result from inheriting a type B allele from the father and a type A allele from the mother.