Alleles are the variation of the gene forms present for the specific trait or the attribute on the chromosome. They are the two forms of single genes.
Alleles are the gene alternative for a trait or the characteristic present on the chromosome of the cell. They are the variant form of the trait that can be expressed dominant or recessively in the cell.
They are also genetic information that codes for the expression of the phenotypes and the genotype in the organisms. They carry the information of the same protein but in a different arrangement.
Therefore, option B. two forms of a single gene is the correct option.
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