Difference between recessive Gene's and mutations ?

[paulh]

Hello , I am new to the ball python world and loving it. just wondered what the difference between a recessive gene and a mutation is ? we have a yellow belly pinstripe for example , I was told if we bred him with out classic when shes big enough , we would get half pinstripe. no yellow belly. I'm confused as to how that works ?

IMO, this link is one of the better introductory web pages: http://www.reptileforums.co.uk/forum...ics-101-a.html. See particularly the definitions of dominant, codominant, and recessive.

Genes come in pairs, like socks. All gene pairs are either homozygous or heterozygous. A homozygous gene pair is made up of two identical genes. A heterozygous gene pair is made up of two genes that are not identical. A pair made up of two black socks is homozygous. Two red socks also makes a homozygous pair. A black sock and a red sock makes a heterozygous pair.

All genes are either normal genes or mutant genes. A normal gene is a gene that is present in most of the individuals in the wild. A mutant gene is a gene that is NOT present in most of the individuals in the wild. For example, in ball pythons, the albino (mutant) gene is much less common than the corresponding non-albino (normal) gene.

The exact number of gene pairs in ball pythons is unknown. 20000 pairs is an approximation. There are approximately 300 mutant genes.

A yellowbelly pinstripe ball python has two gene pairs of interest. For convenience, we ignore the other pairs (made up of normal genes).
pair 1 = yellowbelly gene paired with normal gene
pair 2 = pinstripe gene paired with normal gene

The same two pairs in a classic (AKA normal) ball python.
pair 1 = two normal genes
pair 2 = two normal genes

Result of mating these snakes:
normal
yellowbelly
pinstripe
yellowbelly pinstripe
Expect a quarter of the babies to be of each type, but actual results may vary simply from the luck of the draw.