Laboratory Testing
Blood Types

Is it true that if mother is B positive blood group and father is B positive blood group the child's blood group will be only B positive or O positive?


Wiki User

yes it is true that the child would have either B or O positive blood groups only. This is because the father may have the genotype OB if he is heterozygous and BB if he is homozygous. So is the case for the mother. Rh factor determines if the blood group is positive or negative. Since the parents are positive, so would be the child. Thus upon recombination, the only possible blood groups will be O or B.