The data below demonstrate the frequency of tasters and
nontasters of a certain compound in four isolated populations
that are in Hardy-Weinberg equilibrium. The allele for
nontasters is recessive. In which population is the frequency
of the recessive allele highest?
$$ \begin{array}{|c|c|c|c|} \hline
\text{Population} & \text{Tasters} & \text{Nontasters} & \text{Size of Population} \\ \hline
\text{A} & 110 & 32 & 142 \\ \hline
\text{B} & 8{,}235 & 4{,}328 & 12{,}563 \\ \hline
\text{C} & 215 & 500 & 715 \\ \hline
\text{D} & 11{,}489 & 2{,}596 & 14{,}085 \\ \hline
\end{array} $$
The frequency of the recessive allele is given by \(q\), where,
$$ p^2+2pq+\underbrace{q^2}_{\text{homozygous recessive}}=1 $$
We can calculate this for each population. Since the allele for nontasters is recessive,
the frequency of nontasters corresponds to \(q^2\). Take the square root of this value to obtain \(q\).
$$ \begin{array}{|c|c|c|c|c|c|} \hline
\text{Pop.} & \text{Tasters} & \text{Nontasters} & \text{Size of Population} & q^2 & q \\ \hline
\text{A} & 110 & 32 & 142 & 32/142 & 0.47\\ \hline
\text{B} & 8{,}235 & 4{,}328 & 12{,}563 & 4{,}328/12{,}563 & 0.59 \\ \hline
\text{C} & 215 & 500 & 715 & 500/715 & 0.84 \\ \hline
\text{D} & 11{,}489 & 2{,}596 & 14{,}085 & 2{,}596/14{,}085 & 0.43 \\ \hline
\end{array} $$