What is the term for one of the different forms of a gene?

An allele refers to one of the different forms of a gene that can exist at a specific locus on a chromosome. Genes can have multiple variations, and these variations can influence traits in different ways depending on whether the alleles are dominant, recessive, or co-dominant.

For example, a gene that determines flower color in plants may have alleles for red, white, or yellow flowers. Each of these alleles produces a different expression of the trait. The concept of alleles is fundamental in understanding heredity and how traits are passed from parents to offspring.

In contrast, a genotype describes the genetic makeup of an individual, which includes the specific alleles that they possess. Phenotype refers to the observable traits of an organism, which arise from the combined effects of its genotype and the environment. A chromosome is a structure within cells that contains DNA, which carries the genes, including their alleles, along its length. Thus, while these terms are related, 'allele' specifically identifies the variations of a gene itself.