human blood consist of a groups A ,B and O . however, there is one more blood group AB which contains alleles A and B in the same genotype what is this phenomenon called?

Options are not providedin the question, so the complete question is as follows:

human blood consists of groups A ,B and O. however, there is one more blood group AB which contains alleles A and B in the same genotype what is this phenomenon called?

A. coinheritance B. codominance C. incomplete dominance D. polygenic inheritance

B. codominance

Explanation:

Codominance is a phenomenon in which an individual receives genes from each parent. If the genes or alleles are different it means, dominant allele masks the effect of the recessive allele.

Codominance occurs in the case of the AB blood type in humans in which alleles A and B are present in the same genotype.

Hence, the correct answer is B. codominance.