Determine a child's possible blood types if both of the parent's blood types are known using a blood type calculator found at Biology.Arizona.edu. Due to the four possible maternal blood types and four possible paternal blood types, a child can have any of 16 different combinations of ABO alleles.
The gene that encodes for blood type has two alleles, and each allele can be of genotype A, B or O, according to EndMemo. The A and B genotypes are dominant, and the O allele is recessive. If an individual has an A allele and an O allele, the A allele is dominant, and the individual has blood type A. The A and B alleles are of equal dominance when one individual carries one copy of each. This person has blood type AB.