Allele – One letter (pronounced Al-eel)

An allele is a version of a gene. They are usually represented by one letter. It’s easiest to remember what an allele is by picturing it as one letter.

Mnemonic depicting allele this is an inherited trait from mother or father

An eel (allele) can look like a letter.

Example

Magnified diagram of chromosomes and how mother and father alleles are different

Example

B = brown eye colour

b = blue eye colour

Each allele is represented in a punnet square.

NOTE:

In the example below the mother has brown eyes but carries one brown eye allele and one blue eye allele. The father is also brown eyed but again carries one brown eye allele and one blue eye allele.

A so called punnet table showing possible sequence of inherited eye colour alleles

Each letter represents an allele. One allele is inherited from the father and one from the mother.