A woman with type B blood marries a man with type A blood. their first child has type O blood.The couple is expecting their net child. Draw a punnett square showing the potential genotypes of the second child
The possible blood types are AA BB AB AO BO OO.So yes for parents who are blood types A and B they must be AO and BO but if this trait was dominant then this question would be pointless. The letter rever to the different antigens present on the red blood cells in your blood stream. SO although AO is considered A blood it still show both phenotypes it is just that the O phenotype is no antigens. The antigens are used so that white blood cells can recognize your blood cells from intruders.
As for phenotype frequencies it is 25% for AO BO AB and OO