If the mother has a 4th blood group and the father has a 3rd blood group, then what blood groups

If the mother has a 4th blood group and the father has a 3rd blood group, then what blood groups are impossible in children.

Blood groups in humans are inherited according to the type of multiple allelism (codominance), when a gene is represented by three alleles. They are conventionally named A, B and O. In this case, the O allele is recessive in relation to A and B.

The mother has group 4 (AB), the father has group 3 (BB or BO). The genotype of the father is not known – we take BО, because it gives more options.

PP w AB (4) x m BO (3);

m / f B О А AB (4) AO (2) B BB (3) BО (3)
With such genotypes and phenotypes of parents in children, blood group 4 (25%), group 2 (25%) and blood group 3 (50%) are possible.