Micro Chapter 16 Flashcards
Mutations occur A) Spontaneously B) In response to physical or chemical agents C) All of the above D) None of the above
C
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
B
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
A
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
C
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
A
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
C
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
B
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
D
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
D
Which technique is used to screen for auxotrophic mutants? A) Plaque assay B) Replica plating C) Serial dilution D) All of the above
B
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
D
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
C
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
B
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
C
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
A
Horizontal gene transfer (HGT) mechanisms enable creation of recombinants in A) Bacteria only B) Archaea only C) Eukarya only D) Both Bacteria and Archaea
D
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
D
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
D
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
A
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
C
Mobile genetic elements that contain genes in addition to those required for transposition are called A) Insertion sequences B) Transposons C) Mutants D) Recombinants
B
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
C
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
D
The transfer of a plasmid from one cell to another via direct contact is known as A) Transformation B) Transduction C) Conjugation D) Transposition
C
