Population Genetics

Which agent of evolution tends to reduce genetic variation between populations and increase genetic variation within each population?

• mutation

• genetic drift

• inbreeding

• migration

• natural selection

_____ ultimately produces all new genetic variation in a population.

• Mutation

• Migration

• Equilibrium

• Evolution

• Outcrossing

If there is random mating in a population and no evolutionary forces are acting on the population, what will be the expected outcome?

• The genotypic distribution will remain the same, but the allelic frequencies will change.

• The allelic frequencies will remain the same, but the genotypic distribution will change.

• Both the genotypic distribution and the allelic frequencies will remain the same.

• No prediction can be made about the genotypic distribution and allelic frequencies from one generation to the next.

• Both the genotypic distribution and the allelic frequencies will change.

_____ occurs when one allele or trait is favored over another.

• Directional selection

• Overdominance

• Stabilizing selection

• Founder effects

• Mutation–selection equilibrium

By the early 1980s, the population of Florida panthers had dwindled to fewer than 30. Within this population, there was a high frequency of detrimental traits, including low sperm count and undescended testicles in males and kinked tails in both sexes. The future for this iconic population was bleak at best. Which of the following is the BEST solution that would both increase the likelihood that the population would survive and preserve the genetic identity of this unique population?

• The population could be removed and relocated to a better habitat, which should help the population recover.

• Individuals with the genetic abnormalities could be removed from the population.

• There is no viable solution to saving this population.

• Some individuals could be moved so they will mate with specific other, healthier animals, which would assure more mixing of nondetrimental alleles.

• Genetic rescue could be performed, in which panthers from another population would be introduced in order to bring in new genetic variation and to reduce the genetic load.

Through _____, alleles may disappear from a population simply by chance.

• underdominance

• fixation

• negative directional selection

• genetic drift

• genetic rescue

Which agent of evolution is most likely responsible for the decrease in the frequency of a detrimental recessive allele as shown in the accompanying chart?

• genetic drift

• mutation

• assortative mating

• inbreeding

• natural selection

DNA typing is used to compare evidence DNA (E) left at a crime scene to two suspects (S1 and S2). Suspect 1 is excluded by the evidence, but suspect 2 remains included. What is the frequency of suspect 2's genotype if the allelic frequencies in the population are f(A1) = 0.1, f(A2) = 0.2, and f(A3) = 0.7, and the population is at Hardy–Weinberg equilibrium?

• 0.02

• 0.04

• 0.49

• 0.28

• 0.01

_____ is the movement of genes between populations.

• Migration

• Outcrossing

• Genetic drift

• Evolution

• Positive assortative mating

In overdominance, the HIGHEST fitness is found in which genotype?

• mutant

• homozygote for the dominant allele

• heterozygote

• homozygote for the recessive allele

• inbred recessive