How are alleles of particular gene differ from each other ? Explain its significance

Explanation

Alleles are polymorphs that differ in their nucleotide sequence resulting in contrasting phenotypic expression. Alleles are the alternative forms of a same gene, e.g. gens for height have two alleles, one for dwarfness (t) and one for tellness (T). Significance of alleles are
(i) A character may have two or more contrasting phenotypic expressions, thus resulting in variation in a population
(ii) These are used in the studies of inheritance and in understanding their behaviour .