Allele (noun)

1. Either of a pair or series of genes that occupy a specific position on a chromosome and control the same trait, but may have different forms.
2. A variant form of a gene that is located at a specific position on a specific chromosome and that governs a particular characteristic.

Origin:

Early 20th century: from german allel, from alle "all" + -el, on the pattern of pair.

Examples:

1. The blue eye allele is dominant over the brown eye allele.
2. The allele for sickle-cell anemia is inherited from one's parents.
3. The allele for tallness is dominant over the allele for shortness.
4. Scientists have identified a new allele associated with a higher risk of developing a certain type of cancer.
5. Each individual has two alleles for a particular gene, one inherited from each parent.