# College level biology question please help me out 10 points?

The frequency of individuals who cannot taste phenylthiocarbamide (PTC) is approximately 0.3. The inability to taste this bitter substance is due to a recessive allele. Assume that there are only two alleles in the population (namely, tasters, T, and nontasters, t) and that the population is in Hardy-Weinberg equilibrium. What is the frequency of the recessive allele in the population?

A. 0.45

B. 0.30

C. 0.15

D. 0.55

### 1 Answer

- ScienceLv 48 years agoFavorite Answer
Hardy-Weinberg equilibrium= (p2) + (2pq) + (q2) = 1

f(AA)= p²

f(Aa)= 2pq

f(aa)= q²

-------------------------

q²=0.3

q= 0.54

(p2) + (2p*0.54) + 0.3 = 1

p² + 1.09p= 0.7

p*(p + 1.09) =0.7

p=0.7

or

p + 1.09=0.7

p= - 0.39 (a frequency cannot be negative, so the answer is 0.7)

Well, I'm sure my calculations are right. I would suggest you to review those alternatives. :S

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