I'm confuzzled..

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Posted by Serpwidgets on April 21, 2003 at 23:24:36:

In Reply to: I'm confuzzled.. posted by Taceas on April 21, 2003 at 22:22:07:

Am I thinking wrong in thinking that a blizzard is amel x anery B? I thought for me to produce a blizzard, I need one parent amel (or het amel) and one parent charcoal (or het charcoal). Which I would have by having a blizzard female and charcoal male, correct?

You're right on the first count, but wrong on the second count...

(BTW, the highlights here are not yelling, they are intended to stress the importance of the word.)

1- You're right: Blizzard is the expression of both amel and charcoal in the same individual.

1a- this means you need to know what "express" means, and why something is or is not expressed.

2- In order for an animal to express a recessive trait, it must have inherited that trait from BOTH parents.

This is because it inherits a complete set of genetic blueprints for "how to build a cornsnake" from each parent... It gets one set from the sperm, one set from the egg. It has two complete "cornsnake genomes" and therefore has a pair of each gene.

Both genes in the pair will do their thing, and if EITHER gene in the pair knows how to make melanin, it will do so, and the snake WILL produce melanin. This is why BOTH copies must be the recessive one in order for the trait to express itself.

(Now read the above "2-" item over and see if it makes more sense.)

2a- In order for a corn to express BOTH amel and charcoal, it must inherit an amel gene and a charcoal gene... from EACH parent. In all, it must have a PAIR of amel genes and a PAIR of charcoal genes to be a blizzard. And remember, it can only get one amel and one charcoal from each parent.

IOW, each parent must be either het for, or expressing, BOTH traits. If the charcoal is not carrying the amel gene, there's no way any of its sperm or egg will contain the amel gene, and therefore none of the babies will have a pair of amel genes... so therefore none of them will express amelanism.

So if you do charcoal X blizzard, and the charcoal is not carrying (het for) the amel gene, then you won't get any amels or blizzards, ever, no matter what you pair it with.

But, they will have inherited a single amel gene from the blizzard, because her pair of amel genes means she cannot pass down the dominant "melanin-producing" gene. So, all of her babies who don't express amelanism will be known hets for amel.

If the father (charcoal) is not carrying amel, then it is that first generation of babies which are carrying the amel gene AND the charcoal gene... They can then produce blizzards when bred to each other, or the mother.

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