Final Exam Material

There are two isolated populations ("A" and "B") of an endangered plant species. Population A has had a constant size of 2,000 plants and population B has had a constant size of 250 plants. We most expect to see an increase in the frequency of deleterious alleles in population _ due to _. a. B; genetic drift b. A; positive selection c. A; genetic drift d. B; purifying selection e. B; positive selection

a. B; genetic drift

Which of the following traits is likely to be unsuitable for phylogenetic analysis? a. Learned behavior b. Morphology c. DNA and RNA sequences d. Protein sequences e. Development

a. Learned behavior

What would you find at the root of a phylogenetic tree? a. The common ancestor of all species depicted in the tree b. All living species c. The common ancestor of some, but not all, of the species depicted in the tree d. Synapomorphies

a. The common ancestor of all species depicted in the tree

Binomial nomenclature means that species are called a. by their genus name followed by their specific epithet. b. by their family name followed by their specific epithet. c. by their specific epithet followed by their genus name. d. by their specific epithet followed by their family name. e. only by their specific epithet.

a. by their genus name followed by their specific epithet.

A taxon that contains an ancestor and all descendants of that ancestor and no other organisms is considered a. monophyletic b. polyphyletic c. paraphyletic d. species e. root

a. monophyletic

Suppose a hard frost in southern Florida wipes out nearly all of a population of plants. Even though the plant population recovers in numbers after a couple of decades, the genetic variation within that population remains much reduced. What is the most likely cause of the diminished genetic variation? a. Purifying selection b. Population bottleneck c. Gene flow d. Sexual selection e. dominance

b. Population bottleneck

The Hardy-Weinberg equilibrium is not applicable under which of the following conditions? a. Large population size b. No gene flow into or out of the population c. Mating under sexual selection d. No mutations e. Random mating

c. Mating under sexual selection

Natural selection _ on phenotypes and _ on genotypes. a. Natural selection cannot act on phenotypes, either directly or indirectly. b. only acts indirectly; can act directly c. can act directly; only acts indirectly d. only acts indirectly; only acts indirectly e. can act directly; can act directly

c. can act directly; only acts indirectly

Assuming there are only two alleles at a given locus, if the frequency of the recessive allele is 0.3, what is the frequency of the dominant allele? a. 0 b. 0.5 c. 0.3 d. 0.7 e. -0.3

d. 0.7

All of the following statements about the Hardy-Weinberg equilibrium (HWE) are true except: a. Studying the deviations from the HWE model can allow biologists to evaluate which evolutionary mechanisms are acting on a population. b. Expectations of HWE are useful for predicting the approximate genotypic frequencies of a population from its allele frequencies. c. After a perturbation, the genotypic frequencies of a population will return to HWE in a single generation if no evolutionary mechanisms are operating. d. An ideal population that continually stayed in HWE would constantly evolve.

d. An ideal population that continually stayed in HWE would constantly evolve.

___ selection operates if individuals within a population with the smallest and largest body sizes have fewer offspring than those of average body size. a. Sexual b. Disruptive c. Destabilizing d. Stabilizing e. Directional

d. Stabilizing

Suppose individual robins that have longer beaks have somewhat more offspring than those with shorter beaks, and that this has led to increases in beak length over time. We can say that beak size is associated with the _ of the robin, and that there is _ selection operating on beak size. a. genetic structure; directional b. genetic structure; stabilizing c. genetic structure; disruptive d. fitness; directional e. fitness; stabilizing

d. fitness; directional

Which of the following statements about evolution is FALSE? a. Genetic drift can change the genetic makeup of populations over time. b. Nonrandom mating can change the genetic makeup of populations over time. c. Natural selection is one of several mechanisms of evolution. d. Populations, not individuals, evolve. e. Evolution is goal-directed.

e. Evolution is goal-directed.

Evolution by natural selection requires a. None of the provided answers are correct. b. diploid individuals. c. small populations. d. human breeding. e. genetic variation among individuals.

e. genetic variation among individuals.