Microbiology practice exam 4
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
Which of the following conditions must be met for transformation to take place?
A) Bacteria must be in exponential phase of growth
Which of the following is a mechanism of horizontal gene transfer (HGT) in Bacteria and Archaea?
A) Conjugation B) Transformation C) Transduction
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
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
A reciprocal exchange between a pair of DNA molecules with the same nucleotide sequence is called
A) Homologous recombination
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
Which of the following is true of conjugation?
A) Requires physical contact between microbes B) Unidirectional C) Involves plasmids
Which DNA repair mechanism is highly error prone and results in the generation of numerous mutations?
A) SOS response
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
Mutations occur
A) Spontaneously, B) In response to physical or chemical agents
Mutations allowing for substitution of a purine for a pyrimidine or vice versa is called a
A) Transversion mutation
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
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?
B) Excision repair
Conjugation in which the donor transfers chromosomal genes with great efficiency but does not change the recipient into F+ cells is known as
B) HFr conjugation
The phage genome is passively replicated by the host in which of the following cycles?
B) Lysogenic cycle only
Which type of mutation involves a single base substitution that changes a codon for one amino acid into a codon for another?
B) Missense mutation
Which technique is used to screen for auxotrophic mutants?
B) Replica plating
A specific portion of the bacterial genome is carried by transducing particles in
B) Specialized transduction
The uptake of DNA from one bacterial cell, either as a plasmid or as a fragment, by another cell is called
B) Transformation
Mutations allowing for substitution of one purine for another or one pyrimidine for another is called a
B) Transition mutation
Mobile genetic elements that contain genes in addition to those required for transposition are called
B) Transposons
The transfer of a plasmid from one cell to another via direct contact is known as
C) Conjugation
Which of the following is true of replicative transposition?
C) Contains genes coding for transposase and resolvase
Which type of DNA repair mechanism repairs thymine dimers by splitting them with the help of visible light?
C) Direct repair
Mutagens that distort DNA to induce a single nucleotide pair insertion or deletion are known as
C) Intercalating agents
Which of the following is true of insertion sequences of transposable elements?
C) It contains only the gene for the enzyme transposase
What type of mutation converts a sense codon, one coding for an amino acid, to a nonsense codon (i.e., a stop codon)?
C) Nonsense mutation
What is the purpose of the Ames Test?
C) To determine if a substance is a mutagen
Bacterial gene transfer mediated by viruses is known as
C) Transduction
Lysine auxotrophs
D) Are unable to produce lysine, and can only grow on media with lysine added
Horizontal gene transfer (HGT) mechanisms enable creation of recombinants in
D) Both Bacteria and Archaea
The insertion or deletion of one or two base pairs within the coding region of a gene results in a
D) Frameshift mutation