biology 11.1-11.3

Chance changes in allele frequencies within a population are called a. genetic drift. b. gene pool. c. gene flow. d. sexual selection

a

In a population of birds, intermediate beak size is selected against, and both very small and very large beak sizes are favored. What type of selection is this an example of? a. disruptive b. normal c. directional d. stabilizing

a

What increases genetic variation when animals move from one population to another population? a. gene flow b. sexual selection c. genetic drift d. bottleneck effect

a

What is the observable change in the allele frequencies of a population over time called? a. microevolution b. selection c. recombination d. distribution

a

Fighting between male elephant seals over females is an example of a. founder effect. b. intrasexual selection cted: c. bottleneck effect. d. intersexual selection.

b

Genetic variation can arise from a random change in the DNA of a gene. This change is called a(n) a. gene pool. b. mutation. c. allele. d. gene flow.

b

Natural selection that changes the distribution of a trait to favor one extreme phenotype is called a. stabilizing selection. b. directional selection. c. normalizing selection. d. disruptive selection.

b

In stabilizing selection, what occurs in a population? a. The population shifts toward one of two extreme phenotypes. b. Both extreme phenotypes shift toward the middle. c. The intermediate phenotype becomes more common. d. The intermediate phenotype becomes rare.

c

Which term means the crossing of two different species that share common genes? a. population b. recombination c. hybridization d. mutation

c

A measure of how commonly a particular allele occurs in a population is known as the a. gene pool. b. mutation rate. c. phenotype. d. allele frequency.

d

A population that is not undergoing natural selection displays what type of distribution? a. directional b. disruptive c. stabilizing d. normal

d

A problem in all populations influenced by the bottleneck effect is that a. offspring inherit harmful alleles. b. chance no longer affects them. c. alleles can't become fixed. d. genetic variation is lost

d

A small number of birds, blown off course during migration, find an island and colonize it. This population will most likely experience genetic drift as a result of the a. sexual selection. b. bottleneck effect. c. mutations. d. founder effect.

d

The more genetic variation a population has, the more likely it is that some individuals will a. migrate. b. mutate. c. evolve. d. survive.

d

The normal shuffling of alleles during meiosis results in a. mutations. b. hybridization. c. reproduction. d. recombination.

d