Deck 9: Genetic Variation in Populations

Question 1

A genetic polymorphism is a sequence change that is present in at least what proportion of the general population?

A) If it is present at all
B) 1%
C) 5%
D) 10%
E) 25%

Answer 1

1%

Question 2

Which of the following is an assumption that the Hardy-Weinberg law depends on?

A) Random mating
B) There are only two alleles for a gene
C) Positive natural selection
D) Constant mutation rates
E) One allele is dominant to the other in the calculation

Answer 2

Random mating

Question 3

The O blood type is ______ the A and B blood types.

A) Dominant to
B) Recessive to
C) Codominant with
D) Inherited separately from

Answer 3

Recessive to

Question 4

In which of the following cases would a pregnant mother need to be treated with Rh immune globulin?

A) Mother is Rh+, Father is Rh-, Baby is Rh-
B) Mother is Rh+, Father is Rh-, Baby is Rh+
C) Mother is Rh-, Father is Rh+, Baby is Rh-
D) Mother is Rh-, Father is Rh+, Baby is Rh+
E) Mother is Rh+, Father is Rh+, Baby is Rh-

Question 5

What type of mutation is Gln39X?

A) Missense
B) Frameshift
C) Splice site
D) Nonsense
E) Deletion

Question 6

Which of the following is a possible consequence of a nonsense mutation?

A) Dominant negative mutation
B) Truncated protein
C) No translation
D) Protein instability
E) All of the above

Question 7

The Hardy-Weinberg law is important for genetic counseling of autosomal recessive disorders because it allows us to calculate which of the following?

A) Recurrence risk in a family
B) Population frequency of the disorder
C) Carrier frequency
D) Whether an affected is likely to be a homozygote or compound heterozygote
E) Risk to other branches of a family

Question 8

In addition to the risk of graft failure, incomplete HLA matching in bone marrow transplantation is associated with a risk of which of the following complications?

A) Severe anemia
B) Leukemia
C) Graft versus host disease
D) Lymphoma
E) Severe combined immunodeficiency

Question 9

Copy number polymorphisms are generally detected using this method.

A) DNA sequencing
B) Karyotyping
C) Fluorescent in situ hybridization (FISH)
D) Array comparative genomic hybridization (CGH)
E) Southern blot

Question 10

What type of mutation is c.1444g>a?

A) Missense
B) Frameshift
C) Nonsense
D) Splice site
E) Not enough information provided

Question 11

A 25-year old woman needs a kidney transplant and hopes that she can get one from her sister. What is the likelihood that her sister shares the same set of human leukocyte antigen (HLA) haplotypes?

A) 25%
B) 33%
C) 50%
D) 66%
E) 75%

Question 12

Aberrant recombination between which of the following sequences can lead to a deletion?

A) Alu elements
B) Different members of a gene family
C) Mispaired chromosomes
D) Repetitive sequences
E) All of the above

Question 13

This type of genetic variation is detailed in the high-density map of the human genome called the HapMap.

A) Short tandem repeats (STRs)
B) Insertion/deletion polymorphisms (Indels)
C) Single nucleotide polymorphisms (SNPs)
D) Variable number of tandem repeats (VNTR)
E) Copy number polymorphisms (CNPs)

Question 14

When a population has subgroups that tend to remain genetically separate from each other, this is known as:

A) Population selection
B) Natural selection
C) Consanguinity
D) Population subdivisions
E) Population stratification

Question 15

Which of the following is not a chromosome mutation?

A) Translocation
B) Aneuploidy
C) Partial duplication
D) Inversion
E) Partial deletion

Question 16

Because of its high level of informativity, the Federal Bureau of Investigation (FBI) uses a set of 13 of this type of marker for identity testing.

A) STRs
B) Indels
C) SNPs
D) VNTR
E) CNPs

Question 17

The age-dependent increase in replication errors in sperm versus oocytes is caused by which of the following?

A) Oocytes sitting dormant for longer periods of time
B) Increased number of mitotic divisions in developing sperm compared to oocytes
C) Greater chance of exposure to mutagens for sperm
D) Less efficient DNA repair systems in developing sperm
E) Natural selection for variability in sperm

Question 18

The Hardy-Weinberg law relates genotype frequencies with which of the following?

A) Disease frequencies
B) Phenotype frequencies
C) Allele frequencies
D) Mutation frequencies
E) Either A or B

Question 19

Why is it believed that transitions are overrepresented among the disease-causing mutations?

A) Increased susceptibility of guanines to mutagens
B) Weaker hydrogen bonding between A-T pairs
C) Spontaneous deamination of 5-methylcytosines
D) Overrepresentation of cytosine phosphate guanine (CpG) in the genome
E) DNA repair mechanisms work less efficiently on these changes

Question 20

What type of mutation is the g.IVS33+2T>A?

A) Missense
B) Nonsense
C) Insertion
D) Splice site
E) Not enough information is provided

Question 21

For X-linked genetic lethal diseases, in what proportion of cases are mothers at low risk of having a second affected child?

A) 0
B) 25%
C) 33%
D) 66%
E) 75%

Question 22

Which of the following favors the fitness of carriers of deleterious mutations?

A) Genetic drift
B) Gene flow
C) Heterozygote advantage
D) Inbreeding
E) Assortative mating

Question 23

A relatively rare disease allele can be found at high frequencies in particular isolated subpopulations as a result of which of the following?

A) Founder effect
B) Balancing selection
C) Heterozygote advantage
D) Population stratification
E) Gene flow

Question 24

Which of the following terms describes the small, random effects that cause changes to allele frequencies in small populations?

A) Population stratification
B) Natural selection
C) Assortative mating
D) Genetic drift
E) Genetic isolation

Question 25

Which of the following determines the likelihood that an allele will be passed to the next generation?

A) Positive selection
B) Negative selection
C) Fitness of the allele
D) Population frequency of the allele
E) Assortative mating

Question 26

As treatment of hemophilia A improves, the proportion of cases of hemophilia caused by new mutations would be expected to:

A) Increase
B) Decrease
C) Stay the same
D) Approach 0
E) Approach 100%

Question 27

An autosomal dominant disorder with near-zero fitness would be seen in a population as a result of which genetic force?

A) Positive selection
B) Balancing selection
C) Inbreeding
D) New mutation
E) Genetic drift

Question 28

If two deaf people have children together, this deviation from random mating is known as:

A) Inbreeding
B) Population selection
C) Consanguinity
D) Population isolation
E) Assortative mating

Question 29

For an autosomal recessive and autosomal dominant disorder, respectively, what would be the effect on allele frequency of improved treatment for the disorder if it originally had low fitness?

A) Allele frequency would increase in both cases
B) Allele frequency would decrease in both cases
C) Allele frequency would increase, allele frequency would decrease
D) Allele frequency would decrease, allele frequency would stay the same
E) Allele frequency would stay the same, allele frequency would increase