An allele is a form of a gene. Genes are segments of DNA that encode instructions for the development, functioning, and maintenance of an organism. Each gene typically exists in multiple variants called alleles, which can differ in their nucleotide sequence. Different alleles can result in variations in the traits that a gene controls. For example, an allele of a gene responsible for eye color could be the variant that determines brown eyes, while another allele of the same gene could be the variant that determines blue eyes. The dominant or recessive nature of each allele determines the expression and inheritance pattern of traits. The location of a gene on a chromosome refers to its position in the DNA sequence of the chromosome.
