In genetics, what does the term 'allele' refer to?

The term 'allele' refers specifically to a variant form of a gene. Genes have specific locations on chromosomes and can exist in multiple forms in a population, each variant being an allele. For example, a gene that determines flower color in a plant might have one allele for red flowers and another for white flowers. These different alleles can lead to variations in the physical characteristics or traits of an organism.

By understanding that alleles are different versions of the same gene, it becomes clear how genetic diversity arises within a species. Moreover, alleles can be dominant or recessive, influencing whether certain traits are expressed in an organism based on which alleles are present.

Other options do not accurately define an allele. A type of protein is incorrect because it refers to the product of gene expression rather than the gene itself. A specific chromosome refers to the structure that contains genes but does not represent an allele directly. A group of genes is too broad and does not capture the singular concept of an allele being a specific variant of a single gene.