Exam 21: Evidence and Mechanisms of Evolution

In a hypothetical population of sawflies, 20 percent of the population is homozygous for allele A and 45 percent is homozygous for allele a. Assuming that A and a are the only alleles at this locus, what percent of the population is heterozygous?

Use the following to answer questions: Suppose you have a population of flour beetles with 1,000 individuals. Normally the beetles are red; however, this population is polymorphic for a mutant autosomal body color, black, designated by b/b. Red is dominant to black, so B/B and B/b genotypes are red. Assume the population is in Hardy-Weinberg equilibrium, with equal frequencies of the two alleles. -What would be the allele frequencies (red, followed by black) if a population bottleneck occurred and only four individuals survived: one female red heterozygote and three black males?

The exchange of allele b1 for b2 at the b locus does not affect the fitness of individuals. These alleles can thus be considered _______ alleles.

Which of the following statements is false?

Which of the following statements about Darwin is true?

Allele frequencies measure the _______ of a Mendelian population, whereas _______ show(s) how it is distributed among its members.

The sizes of horns in males of a particular beetle have an interesting distribution: the highest frequencies are around 15 millimeters and 30 millimeters, with few individuals in between. Based on this observation, which of the following modes of selection is most likely to be operating on these horns?

Suppose that in a population of 1400, 125 individuals are homozygous for allele A7 and 350 are heterozygous for the allele. The frequency of the A7 allele would be _______.

Which of the following is a benefit of sexual reproduction?

Charles Darwin was influenced by the ideas of the economist _______, who observed that unchecked human population growth leads to famine.

Use the following to answer questions: Suppose you have a population of flour beetles with 1,000 individuals. Normally the beetles are red; however, this population is polymorphic for a mutant autosomal body color, black, designated by b/b. Red is dominant to black, so B/B and B/b genotypes are red. Assume the population is in Hardy-Weinberg equilibrium, with equal frequencies of the two alleles. -If the population in the previous question mated randomly and no other evolutionary forces operated, what would be the allele frequencies of their offspring?

Artificial selection for certain traits in Brassica oleracea (European wild mustard)

Which of the following modes of selection leads to a reduction in variation but no change in the mean?

Which of the following statements is true?

Which of the following statements about fitness and natural selection is true?

Which of the following statements about evolution is false?

Which of the following is not a reason why trade-offs constrain evolution?

A special type of natural selection called _______ acts on characters that determine mating success.

Long-horned cattle have greater difficulty moving through heavily forested areas compared with cattle that have short or no horns, but long-horned cattle are better able to defend their young against predators. This contrast is an example of

Which of the following is not a condition for the Hardy-Weinberg equilibrium?