Alleles that cause an organism to die only when present in homozygous condition are called lethal alleles.

Thus, each gene also has a corresponding homologue, which may exist in different versions called alleles.

Mendel's experiment with tall and short pea plants demonstrates how each individual plant has two particles called alleles.

Mating type genes in ascomycetes are called idiomorphs rather than alleles due to the uncertainty of the origin by common descent.

Alternate forms of a gene are called alleles.

The alternative forms of a factor are called alleles.

These different, discrete versions of the same gene are called alleles.

Sexually reproducing organisms have different sets of genes for every trait (called alleles).

Those variations are called alleles.

The genes controlling eye color have two main forms, called alleles, that code for blue or brown eyes.