2 alleles which are both equally expressed is known as co-dominance, this occurs in the blood when someone has AB blood for example, the A and B alleles have co-dominance.
Codominance is a genetic condition where two different alleles are expressed equally in a heterozygous individual, best illustrated by the ABO blood group system in humans. Here, individuals with one A and one B allele display blood type AB, showing both traits distinctly. This pattern contrasts with complete and incomplete dominance, making codominance unique in its effect on phenotype.
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