What is the genotype that indicates codominance among the offspring?

In genetics, codominance occurs when both alleles in a heterozygous genotype contribute equally and visibly to the organism's phenotype. In this case, the offspring with the genotype AB inherits one allele for type A blood (A) and one allele for type B blood (B). As a result, both A and B traits are expressed in the phenotype, reflecting the principles of codominance where neither allele is dominant over the other.

This contrasts with other genotypes such as AA, AO, and OO, where only one phenotype may be expressed or there may not be visible contribution from both alleles. AA shows complete dominance of the A allele, AO shows that A is dominant over O, and OO indicates a homozygous recessive condition where neither A nor B traits are expressed. Thus, the AB genotype is the only one that illustrates codominance effectively by showcasing both alleles together.