16. When nonrandom mating occurs in a population so that individuals prefer to mate with similar individuals, allele frequencies should A. Remain the same, but homozygotes will be overrepresented in the population. B. Remain the same, but heterozygotes will be overrepresented in the population. C. Change and heterozygotes will be overrepresented in the population. D. Change and homozygotes will be overrepresented in the population. E. Remain the same, at Hardy-Weinberg equilibrium.
17. Cystic fibrosis is a single-gene genetic disorder in homozygous recessives that causes death during the teenage years. If 9 in 10,000 newborn babies have the disease, and assuming that the human population is in genetic equilibrium for this gene, what are the expected frequencies of the dominant (A1) and recessive (A2) alleles?
18. There is a population of beetles that typically have black wings. A scientist studying these beetles knows that their eggs hatch in early spring, the young insects grow through the late spring and summer, they lay eggs in the early fall, and they die in the early winter. Recently some beetles have been born with white wings. Early in life, the black- and white-winged beetles seem to be very similar in number of mating events, eggs laid, and survival rates, but shortly after laying their eggs the white beetles die and there are only black-winged beetles during the late fall. Which of the following is a true statement about the beetles?
19. Three-spined stickleback fish (Gasterosteus aculeatus) show substantial heritable variation in gill-raker length related to differences in their diets. Longer gill rakers appear to function better for capturing open-water prey, while shorter gill rakers function better for capturing shallow-water prey. Which of the following types of selection is most likely to be found in a large lake (open water in the middle and shallow water around the sides) with a high density of these fish?