Micro Chapter 16

Question 1

Mutations occur
	A)	Spontaneously
	B)	In response to physical or chemical agents
	C)	All of the above
	D)	None of the above

Answer 1

C

Question 2

Mutations allowing for substitution of one purine for another or one pyrimidine for another is called a
	A)	Transversion mutation
	B)	Transition mutation
	C)	Frameshift mutation
	D)	Silent mutation

Answer 2

B

Question 3

Mutations allowing for substitution of a purine for a pyrimidine or vice versa is called a
	A)	Transversion mutation
	B)	Transition mutation
	C)	Frameshift mutation
	D)	Silent mutation

Answer 3

A

Question 4

Mutagens that distort DNA to induce a single nucleotide pair insertion or deletion are known as
	A)	Disinfectants
	B)	DNA-modifying agents
	C)	Intercalating agents
	D)	Radiation

Answer 4

C

Question 5

A change in the nucleotide sequence of a codon that does not change the amino acid encoded by that codon is called a
	A)	Silent mutation
	B)	Missense mutation
	C)	Nonsense mutation
	D)	Frameshift mutation

Answer 5

A

Question 6

What type of mutation converts a sense codon, one coding for an amino acid, to a nonsense codon (i.e., a stop codon)?
	A)	Silent mutation
	B)	Missense mutation
	C)	Nonsense mutation
	D)	Frameshift mutation

Answer 6

C

Question 7

Which type of mutation involves a single base substitution that changes a codon for one amino acid into a codon for another?
	A)	Silent mutation
	B)	Missense mutation
	C)	Nonsense mutation
	D)	Frameshift mutation

Answer 7

B

Question 8

The insertion or deletion of one or two base pairs within the coding region of a gene results in a
	A)	Silent mutation
	B)	Missense mutation
	C)	Nonsense mutation
	D)	Frameshift mutation

Answer 8

D

Question 9

Lysine auxotrophs
A) Produce their own lysine, and can only grow on media without lysine
B) Produce their own lysine, and can only grow on media with lysine added
C) Are unable to produce lysine, and can only grow on media without lysine
D) Are unable to produce lysine, and can only grow on media with lysine added

Answer 9

D

Question 10

Which technique is used to screen for auxotrophic mutants?
	A)	Plaque assay
	B)	Replica plating
	C)	Serial dilution
	D)	All of the above

Answer 10

B

Question 11

Microbial mutants can be identified and selected by
A) Growing cells on minimal media
B) Growing cells in the presence of viruses
C) Growing cells on an alternative carbon source
D) All of the above

Answer 11

D

Question 12

What is the purpose of the Ames Test?
A) To identify a microbe’s preferred carbon source
B) To identify potential DNA repair mechanisms
C) To determine if a substance is a mutagen
D) To determine if microbial cells grow in the presence of lysine

Answer 12

C

Question 13

In which DNA repair mechanism is the damaged portion of DNA removed and the intact complementary strand used as a template for synthesis of new DNA?
	A)	SOS response
	B)	Excision repair
	C)	Direct repair
	D)	All of the above

Answer 13

B

Question 14

Which type of DNA repair mechanism repairs thymine dimers by splitting them with the help of visible light?
	A)	SOS response
	B)	Excision repair
	C)	Direct repair
	D)	All of the above

Answer 14

C

Question 15

Which DNA repair mechanism is highly error prone and results in the generation of numerous mutations?
	A)	SOS response
	B)	Excision repair
	C)	Direct repair
	D)	All of the above

Answer 15

A

Question 16

Horizontal gene transfer (HGT) mechanisms enable creation of recombinants in
	A)	Bacteria only
	B)	Archaea only
	C)	Eukarya only
	D)	Both Bacteria and Archaea

Answer 16

D

Question 17

Which of the following is a mechanism of horizontal gene transfer (HGT) in Bacteria and Archaea?
	A)	Conjugation
	B)	Transformation
	C)	Transduction
	D)	All of the above

Answer 17

D

Question 18

What happens to donor DNA when it enters the recipient cell?
A) Integration of the DNA into the recipient’s chromosome
B) Replicates separately from the host DNA in a plasmid
C) Donor DNA remains in the cytoplasm, unable to replicate
D) All of the above

Answer 18

D

Question 19

A reciprocal exchange between a pair of DNA molecules with the same nucleotide sequence is called
	A)	Homologous recombination
	B)	Nonhomologous recombination
	C)	Transposition
	D)	Conjugation

Answer 19

A

Question 20

Which of the following is true of insertion sequences of transposable elements?
A) They are complex transposable elements
B) Is flanked by unique nucleotide sequences
C) It contains only the gene for the enzyme transposase
D) All of the above

Answer 20

C

Question 21

Mobile genetic elements that contain genes in addition to those required for transposition are called
	A)	Insertion sequences
	B)	Transposons
	C)	Mutants
	D)	Recombinants

Answer 21

B

Question 22

Which of the following is true of replicative transposition?
A) Involves the enzyme transposase only
B) Involves the enzyme resolvase only
C) Contains genes coding for transposase and resolvase
D) None of the above

Answer 22

C

Question 23

Transposable elements can produce which of the following effects?
A) Turns genes on or off
B) Inserts a start or stop codon in the middle of a gene
C) Mutations occur
D) All of the above

Answer 23

D

Question 24

The transfer of a plasmid from one cell to another via direct contact is known as
	A)	Transformation
	B)	Transduction
	C)	Conjugation
	D)	Transposition

Answer 24

C

Question 25

What is the role of the genes related to the F factor in conjugation?
A) Aid in DNA transfer
B) Forms sex pili
C) Includes IS elements that assist plasmid integration into the host cell’s chromosome
D) All of the above

Answer 25

D

Question 26

Which of the following is true of conjugation?
A) Requires physical contact between microbes
B) Unidirectional
C) Involves plasmids
D) All of the above

Answer 26

D

Question 27

Conjugation in which the donor transfers chromosomal genes with great efficiency but does not change the recipient into F+ cells is known as
	A)	F+ x F- mating
	B)	HFr conjugation
	C)	F' conjugation
	D)	None of the above

Answer 27

B

Question 28

The uptake of DNA from one bacterial cell, either as a plasmid or as a fragment, by another cell is called
	A)	Conjugation
	B)	Transformation
	C)	Transduction
	D)	Recombination

Answer 28

B

Question 29

Which of the following conditions must be met for transformation to take place?
A) Bacteria must be in exponential phase of growth
B) Bacteria must be in nutrient limited conditions
C) Bacteria must be in the same family
D) All of the above

Answer 29

A

Question 30

Which of the following is the end product of bacterial transformation?
A) DNA is degraded by the host cell
B) Integration of the DNA by non-reciprocal recombination
C) Plasmid is stably transformed into the cell but separate from the chromosome
D) All of the above

Answer 30

D

Question 31

Bacterial gene transfer mediated by viruses is known as
	A)	Conjugation
	B)	Transformation
	C)	Transduction
	D)	Recombination

Answer 31

C

Question 32

The phage genome is passively replicated by the host in which of the following cycles?
	A)	Lytic cycle only
	B)	Lysogenic cycle only
	C)	Both lytic and lysogenic cycles
	D)	None of the above

Answer 32

B

Question 33

A specific portion of the bacterial genome is carried by transducing particles in
	A)	Generalized transduction
	B)	Specialized transduction
	C)	Transformation
	D)	Nonhomologous recombination

Answer 33

B