In a population of 200 guinea pigs, 32 are white-furred. If white fur is controlled by a recessive allele and the population is in Hardy-Weinberg equilibrium, what is the frequency of the dominant allele?

The frequency of white guinea pigs (homozygous recessive, q²) = 32/200 = 0.16. Therefore q = √0.16 = 0.40. Since p + q = 1, the frequency of the dominant allele p = 1 − 0.40 = 0.60. Option A is q², option B is q, and option D is an incorrect subtraction.