alleole

An allele is a variant form of a gene. Genes are segments of DNA that contain the instructions for building proteins, which are essential for the structure and function of cells. Alleles are the different forms of a gene that can exist at a particular locus, or position, on a chromosome. For example, the gene for eye color has multiple alleles, including those for brown eyes, blue eyes, and green eyes.

Alleles can be dominant or recessive. A dominant allele is expressed in an individual's phenotype (observable traits) even if only one copy is present. A recessive allele, on the other hand, is only expressed if two copies are present. For instance, the allele for brown eyes is dominant over the allele for blue eyes, so an individual with one brown eye allele and one blue eye allele will have brown eyes.

Alleles play a crucial role in genetics and evolution. They contribute to genetic diversity within populations, which is essential for adaptation and survival. The study of alleles and their interactions is fundamental to understanding inheritance patterns and genetic disorders.