The given problem shows that the phenotypic frequency is 0.884 (1167/1320) for the dominant trait and 0.116 (153/1320) for the recessive trait. From the given, we can compute for the allele frequencies only by assuming that the population follows Hardy-Weinberg equilibrium. In a Hardy-Weinberg equilibrium, the frequency of the dominant allele can be represented by p, and the frequency of the recessive allele can be represented by q. For a trait that only has two alleles, p + q = 1. Furthermore, these values can be used to compute for the genotypic frequencies: p2 is for the homozygous dominant, 2pq is for the heterozygotes and q2 for the homozygous recessive.
A new kind of orchid is produced that develops only purple or pink flowers. Assume that flower color is controlled by a single-gene locus and that the purple allele (C) is dominant to the pink allele (c). A random sample of 1320 orchids from a large cultivated field yields 1.167 purple flowers and 153 pink flowers. What is the frequency of the pink allele in this field population?
A. pink allele frequency = 0.847
B. pink allele frequency = 0.12
C. pink allele frequency = 0.34
D. pink allele frequency = 0.39
E. pink allele frequency = 0.153