Final answer:
The frequency of the dominant allele is 0.6, which can be calculated using the Hardy-Weinberg principle, considering that the frequency of the recessive phenotype is 16%.
Step-by-step explanation:
When considering a gene with two alleles, such as a dominant allele A and a recessive allele a, the frequency of the recessive phenotype within a population can help us determine the frequency of the dominant allele. If the recessive phenotype occurs in 16% of the population, this corresponds to the frequency of the homozygous recessive genotype (aa), which is q² = 0.16. Using the Hardy-Weinberg principle, where p² + 2pq + q² = 1, we can determine that q, the frequency of the recessive allele, is the square root of 0.16, which equals 0.4. Hence, p, the frequency of the dominant allele, is 1 - q, which is 1 - 0.4 = 0.6. Therefore, the frequency of the dominant allele is 0.6, which corresponds to answer choice E. This calculation takes into account the laws of chance and probability of simple Mendelian inheritance.