double het

what is the difference between a het and double het. Common since tells me a het is just a single visual gene, then a double het would be two different visual genes. But I could be wrong. Please help

a single het would be het albino,or het pied,a double,would be het both,to carry the genes for 2 reccesive morphs

"het" is short for heterozygous, which means having a single copy of (x) gene, in this case lets say albino.

a double "het" is a double heterozygous animal, so it has two different heterozygous genes, lets say for both albino (x) and pied (y).

A double het is an animal that carries the genes necessary to make other recessive morphs, but looks completely normal.

Ball python keepers tend to only use "het" for recessive morphs but the definition of heterozygous is having an unmatched gene pair at whatever locus you are talking about so it also applies to co-dominant and dominant morphs. A bumble bee is a double het. It is heterozygous for pastel because at the pastel locus it has one pastel mutant version paired with one normal for pastel version. Likewise it is also het for spider because at the spider locus it has one spider mutant gene paired with one normal for spider gene. The Punnett square for bumble bee X bumblebee would look just like the one for double het albino pied X double het albino pied except you might use different letters and perhaps capitalization.