Normas,l Breeding Question

[WingedWolfPsion]

Recessive genes are called 'recessive' because they RECEDE behind the dominant genes. There are two copies of every gene in your body. If you have 2 copies of a recessive mutant gene, then the recessive trait will show up. (For example, blue eyes in humans--or albino in ball pythons).

If you have 2 copies of normal-type genes, then you will look normal.

If you have 1 copy of a normal-type gene, and 1 copy of a recessive mutant gene, then you will look normal--the recessive gene RECEDES behind the normal gene, and you only see the normal gene expressed. This animal, carrying just one copy of the mutant gene, and looking normal, will be called Heterozygous. So, 'het for albino' looks normal, but carries 1 copy of the albino gene.

If you breed 2 heterozygous animals together, they each contribute half of the DNA to make the baby snakes. They each have 1 mutant gene, and 1 normal gene, to contribute. It's a coin toss as to which one will wind up being contributed in the eggs/sperm. The odds of an egg with a mutant gene meeting a sperm with a mutant gene are about 25%. The odds of there being 2 normal genes is also 25%. The rest will get one normal gene, and one mutant gene.

So, 25% of their offspring will be albinos, because they didn't inherit any normal genes for the mutant gene to recede behind.

The rest will all LOOK normal, but a third of them will actually be het for albino. Since we don't know which ones, we call them 66% possible hets. There's a 2/3 chance that they carry the albino gene, but you can't be sure until you breed them to another animal with the gene, and see what pops out.