What are alleles?

Alleles are referred to as different forms of a gene. This concept is central to genetics, as alleles can produce variations in traits among individuals. Each gene in an organism's DNA can exist in several different forms—these variations arise from mutations or variations in the genetic sequence. For example, a single gene that determines flower color in a plant might have one allele for red flowers and another for blue flowers.

The presence of multiple alleles for a single gene provides a mechanism for genetic diversity within a population, which can be important for adaptation and evolution. When alleles are inherited from parents, they can lead to different physical traits or phenotypes in offspring, depending on which alleles are present.

In contrast, identical copies of genes would not account for variability, and segments of DNA that do not code for proteins are known as non-coding regions, often referred to as "junk" DNA. Proteins that bind to DNA refer to regulatory proteins that control gene expression, which is a different biological aspect unrelated to the definition of alleles. Understanding alleles is crucial for grasping fundamental concepts in heredity and variation in living organisms.