Punnett Square

I have a question in regards to doing punnett squares. I know the basics of how to set them up with single gene animals. I can also set them up when both animals are double gened. I am just curious how you would set up a square for breeding a single gene morp to a double gene morph. Do you have to add extra filler letters to the single gene? Just something I would find convenient to know instead of using the calculators online.

Brennan

I don't even bother trying to figure it out manually anymore...

www.worldofballpythons.com/wizard

Somebody should have paid attention in high school biology.

If I understand what you're talking about no. Just remember that the recessive gene will only show if there are two of it in the offspring (homozygous). If there is only one, then the animal is heterozygous for that gene and the trait will not show.

Yes I know I can be lazy and use those. I just wanted to understand it better on my own of how that works.

I understand the recessive thing well. I was mostly referring to if I bred a pastel to a spinner how would the punnett square look when setting it up since one snake only has one trait gene and the other has two traits to account for.

Lets say you have a pastel and a bumblebee. Let's say P for pastel and S for spider.

Pastel = Ppss
Spider = ppSs
Bumblebee = PpSs

So you would set it up as Ppss x PpSs
And you would get

25% PP 50% Pp 25% pp
50% Ss 50% ss

Combine the two and you would have

12.5% PPSs super pastel spider (killerbee)
12.5% PPss super pastel
25% PpSs pastel spider (bee)
25% Ppss pastel
12.5% ppSs spider
12.5% ppss normal

ok that makes sense. Just pretending that the pastel has the recessive spider gene when setting it up. That answers my question nicely. Thanks much for that.

There are a few ways to set it up, I find this the easiest....You list all the potential genotypes you can get from each parent, using the above example

Pastel x Bumblebee

Pastel = Ppss
Spider = ppSs
Bumblebee = PpSs

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Originally Posted by All Balled Up

ok that makes sense. Just pretending that the pastel has the recessive spider gene when setting it up. That answers my question nicely. Thanks much for that.

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its not so much that it has a "recessive spider" gene other than it does not have the spider gene. There is no "recessive" spider gene, thus a lower case would signify a normal gene in that locus.

Quote:

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Originally Posted by nock

Somebody should have paid attention in high school biology.

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Are you even ABLE to answer a thread without insulting the OP? Wether or not you have a BS in math means nothing for your character. You are a pompous bully.

Quote:

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Originally Posted by Foschi Exotic Serpents

Are you even ABLE to answer a thread without insulting the OP? Wether or not you have a BS in math means nothing for your character. You are a pompous bully.

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No, apparently this person cannot post without having a sarcastic attitude. Being a pompus bully is a polite way of describing this person.

I'm trying to be a lady and not lower myself to his level...

Quote:

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Originally Posted by All Balled Up

I have a question in regards to doing punnett squares. I know the basics of how to set them up with single gene animals. I can also set them up when both animals are double gened. I am just curious how you would set up a square for breeding a single gene morp to a double gene morph. Do you have to add extra filler letters to the single gene? Just something I would find convenient to know instead of using the calculators online.

Brennan

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One of the things the books do not tell people is that a vertebrate has many thousands of gene pairs. But that is too many to deal with at one time. So, FOR SIMPLICITY, the convention is to ignore every gene pair that either is or can be assumed to be normal in both parents. When one or both parents has a pair of normal genes corresponding to the other parent's mutant gene pair, you fill in the normal gene pair.

All genes are either mutant genes or normal genes.

A normal gene is the most common gene in a given gene pair in the wild population.

A mutant gene is NOT the most common gene in a given gene pair in the wild population.

Example: albino male (aa) x Pastel female (Pp)
A = normal
a = albino

P = Pastel
p = normal

Fill in the previously ignored but now required normal gene pairs:
albino (aa pp) x Pastel (AA Pp)
All other gene pairs either are or can be assumed to be two normal genes. These are ignored.

The sire gives one member of each gene pair to each sperm, and the mother gives one member of each gene pair to each egg.

All of the albino's sperm are a p.
Half of the Pastel's eggs are A P and half are A p.
From here, running the Punnett square is easy.

Hope that helps.

Pretty much what I said, except better representation of albino being recessive which I didn't do properly. Other than that..

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That is a great representation. Definitely makes more sense to me now. I find genes to be very intriguing. Makes me think I should have gotten my degree in biology instead of accounting. haha