Chapter 19 Test Questions

True of false? HRR usually uses a sister chromatid?

True.

Site-specific recombination occurs between homologous sequences of DNA.

false

true and false High numbers of LINEs and SINEs may be due to transposable element activity

true

true or false Transposable elements in bacteria are commonly called insertion sequences

true

A sample of water is tested for mutagens. The water is subjected to a process known as high pressure liquid chromatography which can separate compounds based on their different biochemical properties. As material leaves the HPLC column its absorbance is measured at UV light which is used to detect a variety of different compounds. These readings were recorded as a trace on a graph (top chart in the figure). Fractions from the column are collected and then tested in an Ames assay (bottom chart in the figure). In this assay there were 900 colonies with the solvent alone control. Which fractions contain mutagens? A. 7 and 16 B. 3 and 10 C. 3, 7, 10, and 16 D. None of these fractions appear to contain a mutagen

A. 7 and 16

An example of a suppressor mutation would be A. An intragenic mutation that restores the inactive protein's structure B. An intergenic mutation that increases the activity of a protein performing a different function as the mutated protein C. An intergenic mutation that activates a transcription factor that increases the espression of a normal protein D. A mutation that suppresses cell growth

A. An intragenic mutation that restores the inactive protein's structure

Which of the following may account for the process of gene conversion? A. DNA mismatch repair B. DNA gap repair C. Photolyase activity D. Nucleotide excision repair

A. DNA mismatch repair

The complete loss of either a guanine or adenine from DNA is an example of _____. A. Depurination B. Tautomeric shifts C. Deamination D. Demethylation

A. Depurination

Spontaneous mutations include... A. Depurination, deamination, errors in DNA replication B. UV light, radiation, deamination, depurination C. UV light, radiation, deamination, errors in replication D. UV light, errors in DNA replication, deamination, depurination

A. Depurination, deamination, errors in DNA replication

The formation of a D-loop is associated with which of the following models of recombination? A. Double-stranded break model B. Holliday model C. Single-stranded break model

A. Double-stranded break model

Which of the following genes was mobile in McClintock's experiments with mutable sites in corn? A. Ds B. C C. Sh D. Wx E. All of the answers are correct

A. Ds

The wild-type eye color of Drosophila is red. A single-base mutation can occur that produces a white eye color. What statement is correct regarding this mutation? A. It is an example of a mutation that alters protein function B. Individuals with white eyes have a reversion mutation C. It would be an example of a silent mutation D. The white eyed phenotyope is called an example of a neutral mutation.

A. It is an example of a mutation that alters protein function

The results of the replica plating experiments by the Lederbergs supported which theory? A. Random mutation theory B. Physical adaptation theory C. Both theories D. Neither theory

A. Random mutation theory

Select the correct statement regarding the rate of mutation? A. Rates of mutation per cell generation typically range from 10-5 to 10-9 B. Mutation rates are consistent across species C. Mutation rates are not influenced by environmental conditions D. Mutation rates are constant

A. Rates of mutation per cell generation typically range from 10-5 to 10-9

The Holliday model is used to explain which of the following? A. Recombination between homologous chromosomes B. Recombination between sister chromatids C.The migration of transposons D.The replication of transposons E.The generation of antibody diversity

A. Recombination between homologous

A translocation that moves a gene from an area of euchromatin to heterochromatin would typically cause a(n) _______ in the expression of the gene. A. Reduction B. Increase C. Gene expression would remain the same

A. Reduction

Which enzyme is unique to the retro elements? A. Reverse transcriptase B. Reverse resolvase C. Transposase D. IntegraseE. Reverse integrase

A. Reverse transcriptase

Which types of mutations are least likely to be subjected to natural selection? A. Silent B. Missense C. Nonsense D. Insertion

A. Silent

Beechdrops is a parasitic plant that cannot perform photosynthesis but relies on its host the Beech tree. However, Beechdrops still retains many if not all of the genes for photosynthesis. Snapdragons and gladiolas are common garden flowers that rely on their ability to perform photosynthesis. If you were to compare the gene sequences for these three plants for ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) a protein necessary for photosynthesis what would you predict? A. The differences between gladiolas and snapdragons would most likely be silent mutations while those in beechdrops may be silent or missense B. Since these three plants are not highly related the sequences for RuBisCO would be very different between them C. The differences between gladiolas and snapdragons would most likely be in the second nucleotide of codons while beechdrops would have a higher number of mutations in the third nucleotide of the diffferent codons D. The differences between gladiolas and snapdragons would most likely be missense mutations while those in beechdrops may be silent or missense

A. The differences between gladiolas and snapdragons would most likely be silent mutations while those in beechdrops may be silent or missense

The difference between the polymerases used in translesion syntheis repair and general DAN replication is... A. The polymerase used in translesion synthesis has a pocket that can accommodate the lesions while DNA pol III's pocket cannot B. There is no real difference between the polymerases except that the translesional polymerase is not part of the replication complex C. The polymerase used in translesion synthesis has a pocket that cannot accommodate the lesions, that is part of the mechanism by which the lesions are removed. D. The polymerase used to remove the lesion has a mdofied nucleotide binding pocket allowing for mispairing of nucleotides.

A. The polymerase used in translesion synthesis has a pocket that can accommodate the lesions while DNA pol III's pocket cannot

What would be a set of anticipated results from a "Lederberg" experiment? A. Total number of colonies on a plate: 1500 Total number of resistant colonies on replica plate with T1: 150 B. Total number of colonies on a plate: 1500 Total number of resistant colonies on replica plate with T1: 1500 C. Total number of colonies on a plate: 500 Total number of resistant colonies on replica plate with T1: 1500 D. Total number of colonies on a plate: 1500 Total number of resistant colonies on replica plate with T1: 0

A. Total number of colonies on a plate: 1500 Total number of resistant colonies on replica plate with T1: 150

In the nucleotide excision repair system, which of the following proteins is responsible for recognizing a thymine dimer to be repaired? A. UvrA/UvrB B. UvrC C. UvrD D. UvrE

A. UvrA/UvrB

A mutagen is... A. an agent that can alter the structure of DNA and cause mutations. B. a depurinated base. C. a DNA polymerase without a 5' to 3' exonuclease. D. a deaminated base.

A. an agent that can alter the structure of DNA and cause mutations.

The mechanism for reactive oxygen species to cause mutation is... A. bases are oxidized to a variety of different products which might pair with a different base than the original base would have. B. thymine bases are dimerized which causes a break in the DNA which is not repaired correctly. C. the reactive oxygen species stabilize different tautomeric forms of the bases causing inappropriate pairing. D. guanine is depurinated by the reactive oxygen species and if it is not repaired can result in any base being inserted.

A. bases are oxidized to a variety of different products which might pair with a different base than the original base would have.

Which of the following is an example of a transposable element in humans? A.Alu B.P elements C.Mu D.Ty

A.Alu

A temporary change in the conformation of a nitrogenous base is called ______. A. Depurination B. A tautomeric shift C. Deamination D. None of the answers are correct

B. A tautomeric shift

Which of the following is an application of transposon tagging? A. To test if a transposon is replicative B. As a tool to clone novel genes C. To track the movement of transposons between species D. To inactivate transposons in a genome

B. As a tool to clone novel genes

Most TNRE repeats involve expansion of which codon? A. GAA B. CAG C. ATG D. CCC E. Any codon containing three of the same bases

B. CAG

Which of the following domain types is unique to the heavy chain of the polypeptide? A. V B. D C. J D. C

B. D

Photolyase in yeast is an example of what kind of DNA repair mechanism? A. Recombinational repair B. Direct repair C. Base excision repair D. Mismatch repair E. Nucleotide excision repair F. Nonhomologous end joining (NHEJ)

B. Direct repair

A culture of E. coli bacteria is used to establish several subcultures. Each subculture is then plated and individulal colonies that grow on the agar plates are then tested for their sensitivity to the bacteriophage T1. There is a spectrum of sensitivities where some plates have a high number of resistant colonies and some plates had very few. This data supports which theory? A. Physiological adaptation theory B. Random mutation theory C. Both theories D. Neither theory

B. Random mutation theory

Which of the following processes accounts for the tremendous variation in antibody structure? A. RNA editing B. Site-specific recombination C. Integrase activity D. Physiological adaptation E. Hot spots of mutation in the immunoglobin genes

B. Site-specific recombination

How does position effect influence gene expression? A. Point mutations in promoters frequently occur by this mechanism B. Translocations may result in a promoter that is normally used for one gene now controlling an entirely different gene. C. Since this mechanism relies on recombination it relies on the positioning of one allele so that it is under the control of the other allele. D. Translocations always result in a gene being recombined into an area of heterochromatin.

B. Translocations may result in a promoter that is normally used for one gene now controlling an entirely different gene.

In the following sequence of DNA, the italicized base has been mutated. What type of mutation is this? 5' - G A T C T C C G A A T T - 3' original strand 5' - G A T C T C C C A A T T - 3' mutated strand A. Transition B. Tranversion C. Neither

B. Transversion

Which of the following most likely accounts for the majority of the recombination events during both DNA repair and meiosis? A. A nick in only one strand of the DNA B.Double-stranded breaks in DNA C. DNA gap repair synthesis D. Heteroduplex formation

B.Double-stranded breaks in DNA

An example of a base analog would be A. EMS B. Nitrous acid C. 5BU D. Nitrogen mustards E. Acridine dyes

C. 5BU

What is the difference between a forward and reverse mutation? A. A forward mutation is beneficial to the organism, while a reverse mutation is harmful to the organism. B. A forward mutation changes the genotype to the wild-type genotype, while a reverse mutation changes the genotype to a mutant genotype. C. A forward mutation changes the wild-type genotype to some new genetic combination, while a reverse mutation changes a genotype to the wild-type genotype. D. None of the answers are correct

C. A forward mutation changes the wild-type genotype to some new genetic combination, while a reverse mutation changes a genotype to the wild-type genotype.

What is the selfish DNA theory? A. A theory that explains how DNA point mutations are repaired within the genome. B. A theory that explains how transposable elements are repaired within the genome. C. A theory that attempts to explain the proliferation of transposable elements in a genome by comparing it to the action of a parasite. D.A theory that attempts to explain how the proliferation of transposons improves the evolutionary advantage of the host organism.

C. A theory that attempts to explain the proliferation of transposable elements in a genome by comparing it to the action of a parasite.

Which DNA repair mechanism uses DNA-N-glycolases? A. Recombinational repair B. Direct repair C. Base excision repair D. Mismatch repair E. Nucleotide excision repair F. Nonhomologous end joining (NHEJ)

C. Base excision repair

The conversion of cytosine to uracil in DNA is an example of _____. A. Depurination B. Tautomeric shifts C. Deamination D. Demethylation

C. Deamination

Which of the following is technically not part of the genetic information of a transposable element? A. Long-terminal repeats B. Inverted repeats C. Direct repeats D. Transposase

C. Direct repeats

The individual who first proposed the existence of transposable elements was ____. A. Sturtevant B. Morgan C. McClintock D. Franklin E. Watson

C. McClintock

Translocations and inversions may result in A. TNRE B. Anticipation C. Position effect D. Genome mutations

C. Position effect

Insertion sequences can be identified by which of the following? A. Presence of an integrase enzyme B. High level of mutation C. Presence of inverted repeats at the end of the sequence D. Presence of a reverse transcriptase enzyme

C. Presence of inverted repeats at the end of the sequence

In E. coli, a mutation in the genes encoding which of the following proteins would disable the ability of the cell to recognize double-stranded breaks and conduct recombination during meiosis? A. RecG B. RecA C. RecBCD D. RuvABC

C. RecBCD

Transposons that utilize an RNA intermediate for transposition are called _____. A.IS elements B.Retroviruses C. Retrotransposons D.Non-transposable elements

C. Retrotransposons

Bacteriophage inserts into a bacterial chromosome using which of the following? A. Nucleotide excision repair B. Endonuclease activity C. Site-specific recombination D. DNA gap repair

C. Site-specific recombination

Long-terminal repeats are unique to which group of transposons? A. Composite transposon B. Non-viral retro element C. Viral-like retro element D. Replicative transposon E. Insertion sequence

C. Viral-like retro element

After screening a colony of bacteria for mutations in a given gene, you discover 100 mutant colonies out of 3 million total colonies. What is the mutation frequency for this gene in the population? A. 1.0 x 105 B. 1.0 x 10-5 C. 3.0 x 105 D. 3.3 x 10-5

D. 3.3 x 10-5

Mutations that change the configuration of a protein at a specific temperature are called ____ mutations. A. Neutral B. Beneficial C. Deleterious D. Conditional

D. Conditional

Which repair mechanism identifies daughter strands by methylation? A. Recombinational repair B. Direct repair C. Base excision repair D. Mismatch repair E. Nucleotide excision repair F. Nonhomologous end joining (NHEJ)

D. Mismatch repair

Which repair mechanism utilizes MutL, MutH, and MutS proteins in E. coli? A. Recombinational repair B. Direct repair C. Base excision repair D. Mismatch repair E. Nucleotide excision repair F. Nonhomologous end joining (NHEJ)

D. Mismatch repair

Which repair mechanism is responsible for repairing damage from UV radiation? A. Recombinational repair B. Base excision repair C. Mismatch repair D. Nucleotide excision repair E. Nonhomologous end joining (NHEJ)

D. Nucleotide excision repair

Anticipation is associated with which type of mutation? A. Nonsense mutations B. Up-promoter mutations C. Intergenic supressors D. TNRE mutations E. None of the answers are correct

D. TNRE mutations

Which of the following enzymes is required for a transposon to move? A. Integrase B. Jumpase C. Splicase D. Transposase

D. Transposase

Which is not an example of a induced mutational mechanism? A. DNA replication errors B. Tautomeric shifts of nucleic acid bases C. Aberrant recombination D. UV light E. Transposable elements

D. UV light

Which of the following describes attP and attB of bacteriophage ? A. Specific proteins in the cell membrane B. A unique set of phospholipids that identify the organelle of interest C.Glycoproteins in the cell wall D.Specific DNA sequences that are recognized by integrase

D.Specific DNA sequences that are recognized by integrase

An example of a mutagen that integrates into the double-helix of DNA resulting in the inhibition of DNA replication would be A. EMS B. Nitrous acid C. 5BU D. 2-amino purine E. Acridine dyes

E. Acridine dyes

RAG1 and RAG2 proteins are associated with which of the following? A. Recombination during prophase I of meiosis B. Nucleotide excision repair C. Transposition D. Integration of a bacteriophage into the host genome E. Site-specific recombination in antibody genes

E. Site-specific recombination in antibody genes

Which repair mechanism often leads to deletions in chromosomes? A. Recombinational repair B. Direct repair C. Base excision repair D. Mismatch repair E. Nucleotide excision repair F. Nonhomologous end joining (NHEJ)

F. Nonhomologous end joining (NHEJ)

True of false? A change in the chromosome number is called a point mutations.

False.

True of false? An individual that is a genetic mosaic would be the result of a germ cell mutation.

False.

True of false? Somatic cells are those that give rise to sperm and egg cells.

False.

True of false? The most common genotype in a population is called the mutant genotype.

False.

True of false? The term polarity is associated with mutations in eukaryotic cells.

False.

True or false? A mutation in a promoter region that causes the promoter sequence to more closely resemble the consensus sequence is called an up promoter mutation and results in a decrease in transcription.

False.

True or false? Darwin's theory of natural selection supported the physical adaptation theory.

False.

True or false? Ethyl methanesulfonate (EMS) is an example of a deaminating agent.

False.

True or false? Evolution is the result of selecting only those mutations that result in an increased reproductive success.

False.

True or false? TNRE repeats frequently result in the addition of extra histidine amino acids to the protein.

False.

True or false? The mutation frequency would be the same for all genes in a given culture.

False.

True of false? Silent mutations are possible due to the generate nature of genetic code.

True.

True of false? The Ames test may be used to determine if an agent is a mutagen.

True.

True of false? The mutation frequency is the ratio of the number of mutant alleles to the total number of alleles in a given population.

True.

True or false? A heritable change in the genetic material is called a mutation.

True.

True or false? A mutation in one gene that compensates for a mutation in another gene to result in the wild-type phenotype is called an intergenic suppressor mutation.

True.

True or false? Breakpoints in chromosome can lead to mutant phenotypes when they occur in the middle of the gene.

True.

True or false? The process of replica plating was designed to test if mutations occurred in response to a selective agent or if mutations were naturally present in the population before selection.

True.

true or false The human genome contains a unique gene for each immunoglobulin produced.

false

true or false In eukaryotic organisms, a single-stranded break in the DNA is required before recombination can begin during meiosis.

false

true or false To date, there are not any indications that transposable elements offer a selective advantage to a species.

false

true or false Ty is an example of a retro element in the human genome.

false

true or false? The process of recombination occurs during metaphase I of meiosis

false

true or false? Recombination between sister chromatids produces new combinations of alleles that may be beneficial to the species.

false

true or false A bacteriophage that has integrated into the bacterial chromosome is called a prophage

true

true or false The integrase enzyme is responsible for inserting bacteriophage into the host genome.

true

true or false? A heteroduplex is a DNA double helix that contains mismatches.

true

true or false? Transposase is involved with removing the transposable element from its current location.

true