Punnett Squares

Genetics as it applies to evolution, molecular biology, and medical aspects.

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xllxashleexllx
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Punnett Squares

Post by xllxashleexllx » Mon Jan 09, 2006 6:01 am

I have to do punnett squares on one of my exams but i dont understand them. Could someone help????

Thank You
Ashlee :)

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mith
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Post by mith » Mon Jan 09, 2006 3:29 pm

do a forum search, we have many examples.
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Post by xllxashleexllx » Tue Jan 10, 2006 5:05 am

OK thank you


Ashlee

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Post by xllxashleexllx » Fri Jan 20, 2006 6:34 am

Ok I looked at them did i do this right?

the first one is Rrtt
Rt tr
Rt tr

the second one is rrTt
rt Tr
rt tr

Are they right???

Ashlee

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Post by Dr.Stein » Fri Jan 20, 2006 7:06 am

You need to be consistent, when you place R or r in the first place, then it should be always there :)
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Post by bearhug » Fri Jan 20, 2006 12:28 pm

Have you ever heard of the FOIL method in math? If it helps use that same method for monohybrid cross.
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Post by xllxashleexllx » Sat Jan 21, 2006 4:54 am

no what is the FOIL method?


Ashlee

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Post by mith » Sat Jan 21, 2006 5:01 am

http://www.algebrahelp.com/lessons/simp ... oilmethod/

If you think about it, a punnet square is just a 2X2 multiplcation table.
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Re: Punnett Squares

Post by Enzyme » Sat Jan 21, 2006 10:21 pm

xllxashleexllx wrote:I have to do punnett squares on one of my exams but i dont understand them. Could someone help????

Thank You
Ashlee :)


Punnet squares show the allelic combinations of the gametes of each parental and say the possible proportions of the offspring. In one of the axis of the square, you have to put the gametes of one parental and in the other axis you have to put the gametes of the other parental. Then, you have to do the combinations and to write them in their corresponding spaces in the Punnet square.

Here you have an example:
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Post by MariaNovoa » Sun Jan 22, 2006 9:10 pm

please!!!!!!!!!! :shock: i have a test 2morrow in my biology class and i dont understand the punnet square! i understand that the capital letter is Dominant and the lower case letter is reccessive, i also understand that genotype is the genetic makeup and phenotype is the physical characteristes, i got the concepts clear. but what does dominant and recessive has to do with genotype and phenotype, how do i place the letters in the punnet square and how do i get the ratios! please help me!
Email me or aim at [email protected] or at my email address [email protected]!...PLEASE HELP ME
>MaRia NovOa<

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Post by Poison » Mon Jan 23, 2006 3:44 pm

No need to double-post things. I think Enzyme's post explains it. There are some more topics too. Search the forum.
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Post by Dr.Stein » Tue Jan 24, 2006 7:39 am

MariaNovoa wrote:please!!!!!!!!!! :shock: i have a test 2morrow in my biology class and i dont understand the punnet square! i understand that the capital letter is Dominant and the lower case letter is reccessive, i also understand that genotype is the genetic makeup and phenotype is the physical characteristes, i got the concepts clear. but what does dominant and recessive has to do with genotype and phenotype, how do i place the letters in the punnet square and how do i get the ratios! please help me!
Email me or aim at [email protected] or at my email address [email protected]!...PLEASE HELP ME

How could you don't understand the punnet square? What were you doing in class? You can ask your teacher, classmates, you can study together. I am sure they would like to help you. I only can wish you a good luck :)
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