homework help!!!

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westernbio129
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homework help!!!

Post by westernbio129 » Wed Feb 11, 2009 2:43 am

The organic compound PTC tastes bitter to most persons. Inability to taste PTC is caused by having the homozygous recessive genotype "tt". In the US about 70% can taste PTC. What is the frequency of the taster "T" and the non-taster "t" genes?

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whizzbee
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Post by whizzbee » Wed Feb 11, 2009 4:55 pm

70 % of the people can taste PTC
30 % can't
30% = 0.3

non-taster = tt = t^2 = 0.3
t = square root of 0.3
T = 1 - square root of 0.3
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GeGnome
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Re: homework help!!!

Post by GeGnome » Thu Feb 12, 2009 7:46 am

Hardy-Weinberg Equilibrium: P^2 + 2pq + q^2 = 1; p + q = 1

Frequency of those who can taste PTC: 70% = 0.7
Frequency of those who can't taste PTC: 30% = 0.3

T = p
t = q

tt = 0.3 = p^2
p = 0.3^(1/2)
q = 1 - p
This was derived from p + q = 1

Frequency of those with a "T" = q
Frequency of those with a "t" = p

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