Critical thinking predicting if a woman with type o blood and a man with type ab blood have children, what are the children's possible genotypes?

Parent #1 has the alleles of  IA and iParent #2 has the alleles of IB and iA punnet squares is a simple diagram that illustrates the possible genotypes of the offspring of these two people. Parent #1 is across the top and Parent #2 is along the side        IA    iIB    AB   IBii       IAi    ii
For IA or IB will be dominant to i. So for phenotype purposes their offspring have a 25% chande of being AB, 25% chance of B, 25% chance of A and a 25% change of type O (ii)

Crossing over creates new combinations of genes in the gametes that are not found in either parent contributing to genetic diversity