Punnett squares

[tonyj]

Please help me to better understand the Punnett square combinations that are shown on Tim Cranwill's Captive Bred Snakes website.

This is an excellent site for many reasons, but the genetics section is particularly informative.

I am looking at the very last example which illustrates how one would produce a "Snow Ball Python".

This clearly explains how the one in sixteen chance of producing a "Snow" comes into effect.

My question is what each of the other squares would represent.

Am I correct in my interpretation of the 16 squares as follows?;

Statistically there could be,
1 Normal
3 Albinos
3 Anerys
2 Het for Albino
2 Het for Anery
4 Dbl Het for Anery/Albino
1 Snow

Thanks Tim; I hope you don't mind me using your site for my homework.

[HeatherRose]

I'm going to assume this is in the wrong forum Where did you mean to post it?

[tonyj]

Sorry, I think it should be in the breeding section, or general issues.

[HeatherRose]

Done I'd answer, but punnett squares scare me :S

[CHRISANDBOIDS14]

It depends if you adults are albino het axanthic and axanthic het albino, or Double Het snows(normal het axanthic+albino).

Check out:

ralphdavisreptiles.com

Go to the matrix, then punnet squares. He has some really good punnet square info.

HTH.

C.

[Tim_Cranwill]

Hi Tony. I hope I don't ruin the mark you get on your homework!

In this table, what you would get is a bit tough to explain without writing a lot but here goes...


4/16 will be albinos
4/16 will be axanthic
Of those 8 babies, 1 will be both albino AND axanthic or a snow.

Of the 3 albinos that aren't axanthic, 2 will be het axanthic and one will not be het axanthic. So the each albino is 66% het axanthic. The same goes for the axanthics being 66% het albino.

Now for the normals. You should get 9/16 (based only on the "odds") and out of the 9, 4 should be het axanthic and 4 should be het albino. 1/2 of the het axanthics should be het albinos as well and vice versa. 2/9 will only be het albino and 2/9 will only be het axanthic. 1/9 won't be het for either. Now THAT'S the confusing part! lol
<table border=2 bordercolor=black cellpadding=3 cellspacing=3 width="200" height=200><tr><td bgcolor=black>.</td><td bgcolor="cccccc" align=center><b>AE</b></td><td bgcolor="cccccc" align=center><b>Ae</b></td><td bgcolor="cccccc" align=center><b>aE</b></td><td bgcolor="cccccc" align=center><b>ae</b></td></tr><tr><td bgcolor="cccccc" align=center><b>AE</b></td><td align=center>AAEE</td><td align=center>AAEe</td><td align=center>AaEE</td><td align=center>AaEe</td></tr><tr><td bgcolor="cccccc" align=center><b>Ae</b></td><td align=center>AAEe</td><td align=center>AAee</td><td align=center>AaEe</td><td align=center>Aaee</td></tr><tr><td bgcolor="cccccc" align=center><b>aE</b></td><td align=center>AaEE</td><td align=center>AaEe</td><td align=center>aaEE</td><td align=center>aaEe</td></tr><tr><td bgcolor="cccccc" align=center><b>ae</b></td><td align=center>AaEe</td><td align=center>Aaee</td><td align=center>aaEe</td><td align=center>aaee</td></tr></table>


P.S. I'm not sure why it has to be stuck so far down but oh well!

EDIT: Figured it out! It took up as much space as the HTML code took up!

[tonyj]

Thanks everyone!

Tim, truth is, it's years since I did any real homework; it's harder now but much more fun.

I will now try to review it all from scratch again. I think we're getting closer. Perhaps not to a Snow but to understanding what has to be done in order to get there.

[Tim_Cranwill]

LOL, when you said homework I assumed you meant an assignment in school!

Let me know if you have any questions or points you'd like to discuss. I'm no wiz but I have a decent grasp on the basics needed for most snake projects.

Email me if you like: cranwill@mts.net

[Mustangcsa]

Ok so if all the albino's are 66% poss het for axanthic and all the axanthic babies are 66% poss het for albino then what would you call all the normals? Like if you were going to sell them or something what would you say, ##% poss het for ????, they are?

[Tim_Cranwill]

Possible double het for snow? I'm actually not sure what people would call them.

[Mustangcsa]

So maybe like 50% possible double het for snow? I could be way off though. Sorry I just always wondered about that after looking at that punnett square. Oh and by the way, great site Tim.

[thunder]

no. they would be called 66% possible double het for snow. this means that they have a 66% chance of being het for albinio, and a 66% chance of being het for axanthic. you don't need to calculate out the chance of them being het for both. but, just in case you care, there is a 37.5% chance of them being het for both.