a woman with type O blood has children with a man who is homoozygous for type B blood. if she were to need a blood transfusion, what is the predicted percentage of her children she could receive blood from

There is a 0% chance that a child can donate blood

Explanation:

Since the O gene is recessive, if the mother is type O then she can only give the O gene.

If the father is homozygous for gene B, then he can only give that gene B which is the only one that has

Since gene B is dominant and your children will have an OB combination, then all your children will have type B blood.

To donate blood to a person O, you need to have blood type O. So none of your children can donate blood