Help needed with Punnet tables!!!

[Felix the snake]

Hi all,

I'm having a bit of difficulty with punnet tables! ):


Do you put all the possible combinations of genes from first part of the pair (sorry dont know the name) and second then put them in one axis of the table? (Then repeat for the other axis).

(Hope that makes sense?)


I know what the babies will be, but could somebody please show me an example punnet table or a Normal het. Anery crossed with another Normal het. Anery?



Is there any good reading on the internet that will help me with genetics and punnet tables (apart from here ), and which are the best books on genetics?



Thank you!


andy

 

[Joejr14]

Normal het anery x Normal het anery

Both parents will pass along a gene pair looking like this: Aa (where A=anery)

Each pair goes along one axis of the punnett square.

So,

----A------a

A--AA-----Aa


a--Aa-----aa

Aa is normal het for anery, AA is normal, and aa is anery.

 

[Felix the snake]

thanks for the help.


arent the genes paired, e.g. a normal corn would be RBRB, not just RB?

So would a normal het anery = AaAa?

 

[Joejr14]

thanks for the help.


arent the genes paired, e.g. a normal corn would be RBRB, not just RB?

So would a normal het anery = AaAa?

No, a normal het anery would be Aa. You've got pairs as in RR, BB, XX, CC, DD, etc. RB isn't correct, it would be RRBB.

 

[Felix the snake]

"What happens if we cross one double heterozygote with another. First, what are the possible gametes produced from a RrBb snake. There are 4 possiblities: RB, Rb, rB and rb. They are each equally possible, so 25% of the gametes will be RB, 25% Rb, etc etc. To determine the geneotypes and phenotypes of the offspring from this cross, one takes the possible gametes and forms a Punnett Square. Since each snake can form 4 different gametes and since these can each combine randomly, there are 16 different combinations of genotypes for the offspring. These are shown below in the Punnett Square.


RB Rb rB rb
RB RRBB RRBb RrBB RrBb
Rb RRBb RRbb RrBb Rrbb
rB RrBB RrBb rrBB rrBb
rb RrBb Rrbb rrBb rrbb
"


I found this on the internet.


is it contradictive or just me?


can anyone explain?

 

[antsterr]

That is a proper double het Punnett Square.

Check out the genetics write up over at serpwidgets

http://serpwidgets.com/Genetics/genetics.html

 

[Felix the snake]

excellent!!!

thats what i wanted.


now all i need is a guide to all the different morphs.


e.g. using A's for normal etc.


Or do you just create your own?

 

[Fenderplayer108]

excellent!!!

thats what i wanted.


now all i need is a guide to all the different morphs.


e.g. using A's for normal etc.


Or do you just create your own?

.
You could use your own letters, you would just have to state what you are wanting the letter to represent.
.
Ryan,
Lifesong Photos

 

[Felix the snake]

thought so.

thanks for all the replys!

appreciated.

 

[MichaelBoyko]

Or go back to that page by serpwidgets, pull out your visa, and buy the cornsnake morph guide. It is highly recommended by the likes of me! Plus it is inexpensive! It will have everything you ever wanted to know. Supplement it with your conversations on this forums and I promise you'll be happy.

 

[Ssthisto]

excellent!!
thats what i wanted.
now all i need is a guide to all the different morphs.
e.g. using A's for normal etc.
Or do you just create your own?

Though "A" for normal would only apply in one gene pair - for example:

AA = normal (no mutation)
Aa = normal (het amelanistic)
aa = Amelanistic

EE = normal (no mutation)
Ee = normal (het anerythristic)
ee = Anerythristic

AaEe = Normal (het amelanistic / anerythristic = 'het snow')

For each gene pair when you're talking about morphs, there is always a "wild type" normal gene and one or more mutant genes.

 

[Nanci]

Cornsnake Morph Guide is really good for getting you comfortable with Punnet squares- running you through increasingly complex crosses.

Nanci