Question 1

DNA repair mechanisms occur

Accepted Answer

A)   only in prokaryotes.
B)   only in eukaryotes.
C)   in both eukaryotes and prokaryotes.
D)   in neither eukaryotes nor prokaryotes.
E)   None of the answer choices is correct.F) B) and C)
G) B) and E)

Question 2

You are a volunteer for Nurses Without Borders and are being sent on a humanitarian mission. You are somewhat concerned because you have learned from the CDC website that antibiotic-resistant Haemophilus influenzae is common in the country to which you are being sent. This encapsulated, Gram-negative bacterium can cause a variety of illnesses, including community-acquired pneumonia. You do some research on the genetics of this pathogen. 
-What concerns you most about the strain of H. influenzae that you may be exposed to while you are away is antibiotic resistance. The genes for resistance can be acquired by this organism as naked DNA from the environment, an example of

Accepted Answer

A)   conjugation.
B)   transformation.
C)   induced mutation.
D)   vertical gene transfer.
E)   transduction.F) A) and C)
G) A) and D)

Question 3

A bacterial strain is resistant to infection by a bacteriophage. Which statement is False?

Accepted Answer

A)   The bacteria make restriction enzymes that degrade the virus genome.
B)   The bacterial host DNA is protected from restriction enzyme degradation by phosphorylation.
C)   The bacterial host DNA is protected from restriction enzyme degradation by methylation.
D)   If the phage DNA was methylated, it would be protected from restriction enzyme degradation.
E)   The statements are ALL False.F) None of the above
G) C) and D)

Question 4

DNA is protected from restriction enzymes by being

Accepted Answer

A)   sequestered in a lysosome.
B)   turned into RNA.
C)   methylated.
D)   made into double-stranded RNA.
E)   phosphorylated.F) A) and B)
G) A) and C)

Question 5

To maximize the number of thymine dimer mutations following UV exposure, should you keep human cells in tissue culture in the dark, in the light, or does it matter at all?

Accepted Answer

A)   The dark-light will activate the photorepair systems that can break thymine dimers induced by UV light.
B)   The light-it's important to keep on producing the thymine dimers by keeping the plate exposed to light as much as possible.
C)   Alternating light and dark every hour to increase the chances that thymine dimers will form, but prevent photorepair systems from correcting them as they are formed.
D)   It doesn't matter-human cells don't have the enzymes needed for photorepair of thymine dimers.
E)   Alternating light and dark every 24 hours to increase the chances that thymine dimers will form.F) None of the above
G) B) and C)

Question 6

Bacteria that have properties of both the donor and recipient cells are the result of

Accepted Answer

A)   UV light.
B)   SOS repair.
C)   frame shift mutations.
D)   genetic recombination.
E)   antibiotic resistance.F) B) and E)
G) B) and C)

Question 7

Organisms termed his⁻ are considered prototrophic for histidine.

Accepted Answer

A) True 
 B)False

Question 8

To increase the proportion of auxotrophic mutants in a population of bacteria, one may use

Accepted Answer

A)   direct selection.
B)   replica plating.
C)   penicillin enrichment.
D)   individual transfer.
E)   mutant reversion.F) A) and B)
G) All of the above

Question 9

Every 24 hours, every genome in every cell of the human body is damaged 10,000 times or more. Given the possible DNA repair mechanisms, which order listed below would be most effective at repairing these as quickly as possible in order to prevent mutations from being carried forward in DNA replication?

Accepted Answer

A)   Proofreading by DNA polymerase, glycosylase enzyme activities, excision repair, SOS repair
B)   SOS repair, excision repair, glycosylase enzyme activities, proofreading by DNA polymerase
C)   SOS repair, proofreading by DNA polymerase, glycosylase enzyme activities, excision repair
D)   Glycosylase enzyme activities, SOS repair, proofreading by DNA polymerase, excision repair
E)   Proofreading by DNA polymerase, SOS repair, glycosylase enzyme activities, excision repairF) A) and B)
G) A) and E)

Question 10

To increase the chance of detecting carcinogens in the Ames test, the test substance is treated with

Accepted Answer

A)   penicillin.
B)   heat.
C)   ground-up rat liver.
D)   reverse transcriptase.
E)   penicillin AND heat.F) C) and D)
G) B) and E)

Question 11

In order for insertional inactivation to occur, the transposon must be placed

Accepted Answer

A)   upstream from the gene in question.
B)   downstream from the gene in question.
C)   within the gene in question.
D)   randomly in the genome.
E)   in an intron.F) A) and B)
G) C) and E)

Question 12

The study of the crown gall tumor found

Accepted Answer

A)   a bacterial plasmid promoter that was similar to plant promoters.
B)   an R plasmid in plant cells.
C)   incorporation of the bacterial chromosome into the plant.
D)   incorporation of the plant chromosome into the bacteria.
E)   a bacterial plasmid promoter that was similar to plant terminators.F) A) and D)
G) None of the above

Question 13

Chemical mutagens often act by altering the

Accepted Answer

A)   alkyl groups of the nucleobase.
B)   nucleobase sequence.
C)   number of binding sites on the nucleobase.
D)   hydrogen bonding properties of the nucleobase.
E)   nucleobases.F) A) and D)
G) A) and B)

Question 14

Antibiotics

Accepted Answer

A)   cause mutations to occur.
B)   may act as alkylating mutagens.
C)   provide an environment in which preexisting mutants survive.
D)   increase the rate of spontaneous mutation.
E)   destroy all mutant bacteria.F) A) and B)
G) A) and C)

Question 15

Two bacterial genes are transduced simultaneously. What does this suggest about their proximity to each other within the original host genome?

Accepted Answer

A)   Nothing. It's highly likely that two separate virus particles were carrying each gene, and that they coinfected the new target cell at the same time. This could mean the two original genes might not even be from the same original host cell!
B)   It's highly likely that the two genes are located next to each other in the host cell chromosome. Since transduction results from a packaging error or an excision error that occurs during the infection cycle of the bacteriophage, the genes must lie close to each other to be transduced into a new cell simultaneously.
C)   They must be within five gene lengths of each other, but not necessarily immediately adjacent. If they were immediately adjacent, the transposons that facilitate the transfer of genetic information between the two cells wouldn't be able to "jump" into them.
D)   It doesn't mean anything. Transduction relies on the ability of a cell to take up foreign DNA. It's possible here that the cell has simply taken up two separate bits of DNA at the same time from the surrounding environment.
E)   It's highly likely that one gene was on the chromosome but the other was actually on a plasmid; if those two elements are in one cell, genes can be transferred simultaneously.F) A) and E)
G) B) and E)

Question 16

Plasmids often carry the information for antibiotic resistance.

Accepted Answer

A) True 
 B)False

Question 17

Each gene mutates at a characteristic frequency.

Accepted Answer

A) True 
 B)False

Question 18

In conjugation, transformation, or transduction, the recipient bacteria is most likely to accept donor DNA

Accepted Answer

A)   from any source.
B)   from any species of bacteria.
C)   from the same species of bacteria.
D)   only through plasmids.
E)   from any source AND only through plasmids.F) B) and C)
G) B) and D)

Question 19

In conjugation the donor cell is recognized by the presence of

Accepted Answer

A)   an F plasmid.
B)   a Y chromosome.
C)   diploid chromosomes.
D)   an SOS response.
E)   an F plasmid AND diploid chromosomes.F) A) and C)
G) A) and B)

Question 20

Among the easiest of the mutations to isolate are those which

Accepted Answer

A)   involve polyploid chromosomes AND allow populations to be measured.
B)   involve antibiotic resistance AND allow populations to be measured.
C)   allow populations to be measured AND use an indirect method for measurement.
D)   involve haploid chromosomes AND involve antibiotic resistance.
E)   use an indirect method for measurement AND involve antibiotic resistance.F) None of the above
G) B) and E)

Exam 8: Bacterial Genetics

In conjugation, transformation, or transduction, the recipient bacteria is most likely to accept donor DNA

Correct Answer
verified

In order for insertional inactivation to occur, the transposon must be placed

Correct Answer
verified

To maximize the number of thymine dimer mutations following UV exposure, should you keep human cells in tissue culture in the dark, in the light, or does it matter at all?

Correct Answer
verified

Chemical mutagens often act by altering the

Correct Answer
verified

Correct Answer
verified

Plasmids often carry the information for antibiotic resistance.

Correct Answer
verified

Organisms termed his⁻ are considered prototrophic for histidine.

Correct Answer
verified

In conjugation the donor cell is recognized by the presence of

Correct Answer
verified

The study of the crown gall tumor found

Correct Answer
verified

Two bacterial genes are transduced simultaneously. What does this suggest about their proximity to each other within the original host genome?

Correct Answer
verified

A bacterial strain is resistant to infection by a bacteriophage. Which statement is False?

Correct Answer
verified

Each gene mutates at a characteristic frequency.

Correct Answer
verified

DNA is protected from restriction enzymes by being

Correct Answer
verified

Antibiotics

Correct Answer
verified

To increase the chance of detecting carcinogens in the Ames test, the test substance is treated with

Correct Answer
verified

Correct Answer
verified

Bacteria that have properties of both the donor and recipient cells are the result of

Correct Answer
verified

To increase the proportion of auxotrophic mutants in a population of bacteria, one may use

Correct Answer
verified

Among the easiest of the mutations to isolate are those which

Correct Answer
verified

DNA repair mechanisms occur

Correct Answer
verified

Exam 8: Bacterial Genetics

In conjugation, transformation, or transduction, the recipient bacteria is most likely to accept donor DNA

Correct AnswerverifiedShow Answer

In order for insertional inactivation to occur, the transposon must be placed

Correct AnswerverifiedShow Answer

To maximize the number of thymine dimer mutations following UV exposure, should you keep human cells in tissue culture in the dark, in the light, or does it matter at all?

Correct AnswerverifiedShow Answer

Chemical mutagens often act by altering the

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Plasmids often carry the information for antibiotic resistance.

Correct AnswerverifiedShow Answer

Organisms termed his⁻ are considered prototrophic for histidine.

Correct AnswerverifiedShow Answer

In conjugation the donor cell is recognized by the presence of

Correct AnswerverifiedShow Answer

The study of the crown gall tumor found

Correct AnswerverifiedShow Answer

Two bacterial genes are transduced simultaneously. What does this suggest about their proximity to each other within the original host genome?

Correct AnswerverifiedShow Answer

A bacterial strain is resistant to infection by a bacteriophage. Which statement is False?

Correct AnswerverifiedShow Answer

Each gene mutates at a characteristic frequency.

Correct AnswerverifiedShow Answer

DNA is protected from restriction enzymes by being

Correct AnswerverifiedShow Answer

Antibiotics

Correct AnswerverifiedShow Answer

To increase the chance of detecting carcinogens in the Ames test, the test substance is treated with

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Bacteria that have properties of both the donor and recipient cells are the result of

Correct AnswerverifiedShow Answer

To increase the proportion of auxotrophic mutants in a population of bacteria, one may use

Correct AnswerverifiedShow Answer

Among the easiest of the mutations to isolate are those which

Correct AnswerverifiedShow Answer

DNA repair mechanisms occur

Correct AnswerverifiedShow Answer

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verified

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