Answer:
Step-by-step explanation:
Blood type is determined by the presence or absence of certain antigens on the surface of red blood cells. The most important blood type antigens are A and B, which are controlled by two genes located on the same chromosome. If an individual has two copies of the A gene, they are said to have type A blood, and if they have two copies of the B gene, they are said to have type B blood. If an individual has one copy of each gene, they are said to have type AB blood, and if they have two copies of neither gene, they are said to have type O blood.
In your scenario, if a man is heterozygous type A blood (AA or AO), and a woman is type O (OO), their offspring can only have type O blood because type O blood is recessive to both A and B. This means that type O blood will only be expressed in individuals who inherit two copies of the O gene, one from each parent.
It's worth noting that the inheritance of blood type is a classic example of codominance, where both alleles are expressed equally and the phenotype of the offspring reflects the presence of both alleles.