Mutations are permanent changes in the DNA. Small mutations in the gene sequence can result in organisms having different versions of a gene. The different versions of a gene are called alleles.

One reason individuals of the same species do not have exactly the same traits is because they have different alleles.
The color of fruits and vegetables is usually controlled by more than one gene and there may be several alleles for each gene. The first cultivated carrots came from the area of Afghanistan and were purple or yellow. Traders carried them to Europe and the Mediterranean where they mutated or crossed with wild varieties resulting in the orange carrots that we are familiar with. Carrots may be white, yellow, orange, red or purple depending on the combination of alleles that they inherit.