Question

With the help of one example, explain the phenomenon of codominance and multiple allelism in the human population.

Answer 1

Hint:Codominance happens when a living thing is found in two copies, or "alleles," of the same gene, and both are expressed. Both traits occur because of one phenotype being superior to the other.

Complete answer:
First we should know about codominance and multiple allelism to answer this question. Co dominance is a process where several alleles are similarly distributed and manifest in the phenotype in a heterozygous state, leading to a condition in which neither dominant nor recessive is the phenotype. Multiple allelism is a disorder in which for a particular trait there not two are and rather multiple alleles, i.e. a gene appears in different allelic types.
Three alleles are used in ABO blood grouping in human beings,$I^A$ $I^B$ and $I^O$ resulting in the various genotypes. $I^A$ $I^B$ and originate in antigens A and B that display co dominance, and when existing together, all of them are represented similarly. Therefore in blood group AB in which all the alleles are found, all antigens are expressed on the blood cells. The three $I^O$ alleles also do not lead in any antigen, and the genotypes result from the three alleles together:

>$I^A$ $I^A$ denotes blood group A.
>$I^A$ $I^O$ denotes blood group A.
>$I^B$ $I^B$ denotes blood group B
>$I^B$ $I^O$ denotes blood group B
>$I^A$ $I^B$ denotes blood group AB
>$I^O$ $I^O$ denotes blood group O

Note: A feature called Punnett square may assist in determining whether a characteristic is co dominant. Punnett square helps to analyze in a test cross all necessary allelic pairings. The potential genotypes of the offspring are determined. It is a schematic for describing alleles in grids and letters.