Faster way to find genotypes without doing a punnet square

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dimmere19
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Faster way to find genotypes without doing a punnet square

Post by dimmere19 » Wed Sep 13, 2006 1:06 am

i have this simple question

the mating between Aa Bb Cc Dd x Aa Bb Cc Dd

Is there a faster way to answer this question without doing a punnet square

Chaddycakes21
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Post by Chaddycakes21 » Wed Sep 13, 2006 1:34 am

Lol, not really. Don't be so lazy. Most of us have had to do them.:)

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Poison
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Post by Poison » Wed Sep 13, 2006 8:23 pm

You can find some mathematical proportions (some say they are the "proportion rules") for that, but they all come from punnet square, so I advise you to do it yourself and find those proportions yourself, then you can use them as a rule.

Here is a site for you to check yourself:

http://www.changbioscience.com/genetics/punnett.html

Good luck. :)
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mith
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Post by mith » Wed Sep 13, 2006 9:12 pm

A punnet square is a multiplication table
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sdekivit
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Post by sdekivit » Sat Sep 16, 2006 3:48 pm

if you search for some of my replies in genetics about genetics, you'll see another method in calculating genotype frequencies.

Assume the chance of every gamete is 1/2 to get passed on to the progeny.

Thus fro example: AaBbCc X AABBCc

--> for the left combination if you want to calculate the probability of passing abc than passing on a = 1/2, so are those of b and c --> combined probability = 1/2 * 1/2 * 1/2 = 1/8

--> right passes on ABc and thus the probability is 1 * 1 * 1/2 = 1/2

thus the genotype frequency of AaBbcc = 1/8 * 1/2 = 1/16.

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