Question 1

The characteristics displayed by an organism in any given environment is its

Accepted Answer

A)  genotype.
B)  archaetype.
C)  mutatotype.
D)  phenotype.E) B) and C)
F) A) and D) D

Question 2

The source of variation among microorganisms that were once identical is

Accepted Answer

A)  antibiotic resistance.
B)  virulence factors.
C)  sigma factors.
D)  mutation.E) A) and C)
F) B) and C)

Question 3

Which change in a gene's DNA sequence would have the least effect on the eventual amino acid sequence produced from it?

Accepted Answer

A)  Deletion of two consecutive nucleotides
B)  Addition of one nucleotide
C)  Addition/deletion of three consecutive nucleotides
D)  Substitution of one nucleotide AND addition of 1 nucleotideE) B) and D)
F) A) and B)

Question 4

Insertion sequences

Accepted Answer

A)  are the simplest type of transposon.
B)  code for a transposase enzyme.
C)  are characterized by an inverted repeat.
D)  can produce pili.
E)  are the simplest type of transposon,code for a transposase enzyme,AND are characterized by an inverted repeat.F) A) and B)
G) C) and D)

Question 5

Some bacteria have a higher incidence rate of thymine dimer mutations following exposure to UV light than others.What might be going on here to lead to this outcome?

Accepted Answer

A)  They may simply have a higher proportion of T nucleotides next to each other in their DNA sequences than other bacteria,leading to more possible dimers being formed.
B)  They may have a stronger expression of photoreactivation enzymes,leading to more thymine dimers being formed and retained.
C)  They may have a weaker expression of photoreactivation enzymes,leading to more thymine dimers being formed and retained.
D)  They may simply have a higher proportion of T nucleotides next to each other in their DNA sequences than other bacteria,leading to more possible dimers being formed AND they may have a stronger expression of photoreactivation enzymes,leading to more thymine dimers being formed and retained.
E)  They may simply have a higher proportion of T nucleotides next to each other in their DNA sequences than other bacteria,leading to more possible dimers being formed AND they may have a weaker expression of photoreactivation enzymes,leading to more thymine dimers being formed and retained.F) A) and D)
G) A) and E)

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) C) and D)
F) A) and B)

Question 7

Prokaryotic cell mutations can be observed very quickly because the prokaryotic chromosome is

Accepted Answer

A)  diploid.
B)  polyploid.
C)  haploid.
D)  polysomal.E) B) and D)
F) B) and C) C

Question 8

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) C) and E)
G) All of the above

Question 9

Each gene mutates at a characteristic frequency.

Accepted Answer

A) True 
 B)False

Question 10

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) C) and D)
F) A) and B)

Question 11

Segments of DNA capable of moving from one area in the DNA to another are called

Accepted Answer

A)  base analogs.
B)  intercalating agents.
C)  transposons.
D)  inverted repeats.E) A) and B)
F) B) and C)

Question 12

Replica plating

Accepted Answer

A)  is useful for direct selection.
B)  is useful for identifying auxotrophs.
C)  uses media on which the mutant will not grow and the parental cell typewill.
D)  is used to store strains of bacteria.
E)  is useful for identifying auxotrophs AND uses media on which the mutant will not grow and the parental cell typewill.F) All of the above
G) B) and C)

Question 13

DNA transfer by conjugation is more efficient in a liquid medium setting,subjected to very mild agitation (stirring) ,rather than on an agar plate format.Why?

Accepted Answer

A)  Direct cell-to-cell contact is required for this process,and this is more likely to be achieved in the plate format than in the fluid format (especially for relatively non-motile types of bacteria) .
B)  Direct cell-to-cell contact isn't required for this process,so the ability to secrete the DNA into the surrounding fluid medium makes the process more efficient than the dry surface of an agar plate.
C)  Direct cell-to-cell contact is required for this process,and this is more likely to be achieved in the fluid liquid format than on an agar plate (especially for relatively non-motile types of bacteria) .
D)  Trick question-it can take place with the same degree of efficiency on either format.It doesn't matter!E) C) and D)
F) None of the above

Question 14

Crown gall is caused by a prokaryote plasmid that can be expressed in plant cells.

Accepted Answer

A) True 
 B)False

Question 15

Mutations are likely to persist after SOS repair,but not after light-induced or excision repair.

Accepted Answer

A) True 
 B)False  True

Question 16

Chemical mutagens that mimic the naturally occurring bases are called

Accepted Answer

A)  nitrogen mustards.
B)  alkylating agents.
C)  base analogs.
D)  nitrous oxide.E) A) and C)
F) All of the above

Question 17

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 E)
G) B) and E)

Question 18

The Ames test is useful as a rapid screening test to identify those compounds that

Accepted Answer

A)  will respond to chemical agents.
B)  are mutagens.
C)  respond to the deletion of DNases.
D)  will protect an organism from cancer.
E)  will respond to chemical agents AND will protect an organism from cancer.F) All of the above
G) B) and D)

Question 19

The transfer of vancomycin resistance from Enterococcus faecalis to Staphylococcus aureus is thought to have involved

Accepted Answer

A)  conjugation.
B)  transformation.
C)  transduction.
D)  transposons.
E)  conjugation AND transposons.F) B) and C)
G) A) and E)

Question 20

Indirect selection

Accepted Answer

A)  is necessary to isolate auxotrophic mutants.
B)  uses media on which the mutant but not the parental cell type will grow.
C)  uses media that reverses the mutation.
D)  uses media upon which neither the parental cell typeor mutant grows.
E)  is necessary to isolate auxotrophic mutants AND uses media upon which neither the parental cell typeor mutant grows.F) B) and D)
G) A) and B)

Exam 8: Bacterial Genetics

The characteristics displayed by an organism in any given environment is its

Correct AnswerverifiedD

The source of variation among microorganisms that were once identical is

Correct AnswerverifiedShow Answer

Which change in a gene's DNA sequence would have the least effect on the eventual amino acid sequence produced from it?

Correct AnswerverifiedShow Answer

Insertion sequences

Correct AnswerverifiedShow Answer

Some bacteria have a higher incidence rate of thymine dimer mutations following exposure to UV light than others.What might be going on here to lead to this outcome?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Prokaryotic cell mutations can be observed very quickly because the prokaryotic chromosome is

Correct AnswerverifiedC

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

Correct AnswerverifiedShow Answer

Each gene mutates at a characteristic frequency.

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Segments of DNA capable of moving from one area in the DNA to another are called

Correct AnswerverifiedShow Answer

Replica plating

Correct AnswerverifiedShow Answer

DNA transfer by conjugation is more efficient in a liquid medium setting,subjected to very mild agitation (stirring) ,rather than on an agar plate format.Why?

Correct AnswerverifiedShow Answer

Crown gall is caused by a prokaryote plasmid that can be expressed in plant cells.

Correct AnswerverifiedShow Answer

Mutations are likely to persist after SOS repair,but not after light-induced or excision repair.

Correct AnswerverifiedTrue

Chemical mutagens that mimic the naturally occurring bases are called

Correct AnswerverifiedShow Answer

In conjugation the donor cell is recognized by the presence of

Correct AnswerverifiedShow Answer

The Ames test is useful as a rapid screening test to identify those compounds that

Correct AnswerverifiedShow Answer

The transfer of vancomycin resistance from Enterococcus faecalis to Staphylococcus aureus is thought to have involved

Correct AnswerverifiedShow Answer

Indirect selection

Correct AnswerverifiedShow Answer

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C

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True

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