Human Genetics, 10th Edition, (Lewis)

Chapter 15: Changing Allele Frequencies

Practice Tests

1
Worldwide, about 1/3 of all marriages occur between people who were born fewer than ten miles apart. This is an example of _____.
A)natural selection
B)genetic drift
C)nonrandom mating
D)migration
2
Albinism is uncommon in the United States but affects 1/200 Hopi Indians. A contributing factor for this high increase is _____.
A)nonrandom mating
B)migration
C)genetic drift
D)natural selection
3
Consanguinity increases the proportion of heterozygotes in the population.
A)True
B)False
4
Endogamy refers to _____.
A)marriage within a community
B)marriage to a brother or sister
C)marriage to a cousin
D)marriage to a person from another country
5
Different allele frequencies from one geographic area to an adjacent area constitute _____.
A)founder effects
B)bottlenecks
C)clines
D)balanced polymorphisms
6
Assume that "school spirit" is a genetically controlled trait. At your university, the dominant allele for "we are #1!" occurs at a frequency of 1.0. At your rival university, the frequency of this allele is 0.3. In an effort to obtain additional funding for your university, you attempt to increase the frequency of the #1 allele at the rival institution by sending your graduates there to live and raise families. This would be an example of _____.
A)nonrandom mating
B)migration
C)genetic drift
D)natural selection
7
One of the conditions that must be met for Hardy-Weinberg equilibrium is that organisms must be free to move from population to population.
A)True
B)False
8
If a small number of individuals are isolated from the larger population and mate only among themselves, allele frequencies may change as a result of _____.
A)nonrandom mating
B)migration
C)genetic drift
D)natural selection
9
An example of ____ would be people on Norfolk Island who are direct descendants of HMS Bounty mutineers.
A)a population bottleneck
B)geographical isolation
C)a founder effect
D)natural selection
10
A ____ occurs when many members of a group die and only a few are left, by chance, to replenish the numbers.
A)population bottleneck
B)geographical isolation
C)founder effect
D)natural selection
11
Genetic drift is a random process.
A)True
B)False
12
Genetic disorders such as Tay-Sachs and BRCA1 breast cancer are more common in Ashkenazi Jewish population because _____.
A)genetically, they are a highly variable group
B)mutations occur at a higher rate in this group
C)their history includes several population bottlenecks
D)selection, mutation, and migration have not occurred
13
Although the present day cheetah populations appear to be the result of two extreme population bottlenecks, the populations seem to be in good shape because _____.
A)there are so many individuals alive today
B)most of the cheetahs are healthy
C)there is migration among the many different populations
D)of the genetic diversity within the populations
14
Founder effect and population bottlenecks are both examples of _____.
A)inbreeding
B)migration
C)nonrandom mating
D)genetic drift
15
Which of the following communities of humans are an example of a founder effect?
A)the Afrikaner population of South Africa
B)the Old Order Amish of Pennsylvania
C)the Mennonites of Pennsylvania
D)All of these
16
For Hardy-Weinberg equilibrium to be maintained, mutation must be _____.
A)occurring at a very low rate
B)occurring in some individuals but not others
C)absent
D)Mutation does not affect Hardy-Weinberg equilibrium.
17
The collection of deleterious alleles in populations is called _____.
A)genetic drift
B)selection
C)genetic load
D)migration
18
A change in the DNA sequence that does not substitute an amino acid does not change the protein, and therefore has no effect on the phenotype. Such a change therefore cannot be subject to natural selection.
A)True
B)False
19
Some mutations can increase an individual's chance of survival.
A)True
B)False
20
Which factor has the least influence on disrupting Hardy-Weinberg equilibrium?
A)nonrandom mating
B)migration
C)mutation
D)genetic drift
21
Natural selection results in differential survival based on phenotype.
A)True
B)False
22
Sickle cell disease illustrates a balanced polymorphism because carriers are resistant to _____.
A)malaria
B)kuru
C)tuberculosis
D)diarrheal disease
23
An extreme example of ____ is seen among the Pingelapese people of the eastern Caroline Islands in Micronesia.
A)a population bottleneck
B)geographical isolation
C)a founder effect
D)natural selection
24
Deleterious alleles can be maintained in a population when heterozygotes have a reproductive advantage. This situation is described as _____.
A)inbreeding
B)geographical isolation
C)a population bottleneck
D)a balanced polymorphism
25
The study of tuberculosis demonstrates the effects of _____.
A)inbreeding
B)geographical isolation
C)a population bottleneck
D)natural selection
26
Full-blown AIDS represents the ____ stage of an HIV infection.
A)first
B)second
C)third
D)fourth
27
Frequencies of different mutations in different populations provide information on the natural history of alleles.
A)True
B)False
28
Mutational analysis in various populations indicates that PKU originated only once.
A)True
B)False
29
Genome-wide association studies have shown that native Tibetans have eight unique SNPs in the gene encoding hypoxia inducible factor 2. This gives them a unique version of the protein which enables them to thrive in the thin Tibetan air. This is an example of ____.
A)positive selection
B)negative selection
C)artificial selection
D)landscape genomics
30
If a population travels (migrates) and picks up new individuals, allele (and genotype) frequencies can change.
A)True
B)False
31
Consanguinity and endogamy increase the proportion of ____ in a population.
A)heterozygotes
B)homozygotes
C)hemizygotes
D)species
32
Smith-Lemli-Opitz syndrome provides patients with protection against _____.
A)malaria
B)fungal infection in fetuses
C)diarrheal disease
D)cardiovascular disease
33
Forces that change allele frequencies include _____.
A)nonrandom mating
B)migration
C)genetic drift
D)mutation
E)natural selection
F)All of the above affect allele frequencies.
Glencoe Online Learning CenterScience HomeProduct InfoSite MapContact Us

The McGraw-Hill CompaniesGlencoe

Please read our Terms of Use and Privacy Notice before you explore our Web site. To report a technical problem with this Web site, please contact the Web Producer.