What is the difference between gene and allele?

Gene and allele are related genetic terms, but they differ in definition and role in inheritance.

Gene is a segment of DNA that carries information for a specific trait or function, such as eye color or height.

Allele is a variant or alternative form of a gene that determines different expressions of the same trait.

Key differences:

• Definition:
  Gene: basic unit of heredity controlling a trait
  Allele: different forms of the same gene

• Function:
  Gene determines a general characteristic; alleles determine variations of that characteristic.

• Number:
  A gene can have multiple alleles; an individual carries two alleles for each gene (one from each parent).

• Example:
  Gene: eye color
  Alleles: brown, blue, green

• Location:
  Both are located at the same position (locus) on homologous chromosomes.

In simple terms: A gene controls a trait, while alleles are different versions of that gene that create variation in that trait.