Micro Practice quiz CH.14

Which of the following is the end product of bacterial transformation? DNA is degraded by the host cell

-DNA is degraded by the host cell -Integration of the DNA by nonreciprocal recombination -Plasmid is stably transformed into the cell but separate from the chromosome

Which of the following is TRUE of conjugation?

A) Requires physical contact between microbes B) Unidirectional C) Involves plasmids

Lysine auxotrophs

Are unable to produce lysine, and can only grow on media with lysine added

Horizontal gene transfer (HGT) mechanisms enable creation of recombinants in

Bacteria and Archaea

Which of the following conditions must be met for transformation to take place?

Bacteria must be in exponential phase of growth

The transfer of a plasmid from one cell to another via direct contact is known as

Conjugation

Which of the following is TRUE of replicative transposition?

Contains genes coding for transposase and resolvase

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

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

Which type of DNA repair mechanism repairs thymine dimers by splitting them with the help of visible light?

Direct repair

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?

Excision repair

Conjugation has only been observed in E. coli bacteria

False

DNA fragments and plasmids taken up via transformation are always integrated into the recipient chromosome.

False

Plasmids must be part of the bacterial chromosome in order to replicate.

False

Successful transposition is strongly dependent on sequence homology.

False

Transformation involves the movement of DNA through viral activities.

False

Vertical gene transfer occurs in all domains of life.

False

Virulent bacteriophages are more likely to transfer DNA via transduction.

False

In horizontal gene transfer (HGT), donor DNA is always incorporated into the recipient chromosome.

False (remember the 4 fates of DNA!)

The insertion or deletion of one or two base pairs within the coding region of a gene results in a

Frameshift mutation

Conjugation in which the donor transfers chromosomal genes with great efficiency but does not change the recipient into F+ cells is known as

HFr conjugation

A reciprocal exchange between a pair of DNA molecules with the same nucleotide sequence is called

Homologous recombination

Mutagens that distort DNA to induce a singel nucleotide pair insertion or deletion are known as:

Intercalating agents

Which of the following is TRUE of insertion sequences of transposable elements?

It contains only the gene for the enzyme transposase

The phage genome is passively replicated by the host in which of the following cycles?

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?

Missense mutation

What type of mutation converts a sense codon, one coding for an amino acid, to a stop codon?

Nonsense mutation

Which technique is used to screen for auxotrophic mutants?

Replica plating

Which DNA repair mechanism is highly error prone and results in the generation of numerous mutations?

SOS response

A specific portion of the bacterial genome is carried by transducing particles in

Specialized transduction

What is the purpose of the Ames Test?

To determine if a substance is a mutagen

Bacterial gene transfer mediated by viruses is known as

Transduciton

The uptake of DNA from one bacterial cell, either as a plasmid or a fragment, by another cell is called

Transformation

Mutations allowing for substitution of one purine for another or one pyrimidine for another is called:

Transition mutation

Mobile genetic elements that contain genes in addition to those required for transposition are called

Transposons

Mutations allowing for substitution of a purine for a pyrimidine or vice versa is called a:

Transversion mutation

During homologous recombination, a DNA heteroduplex forms from strands from each parent molecule.

True

Horizontal gene transfer (HGT) is important to the transfer of antibiotic resistance genes and pathogenicity islands.

True

In SOS repair, the LexA repressor is destroyed resulting in the expression of many DNA repair enzymes.

True

In excision repair, a portion of the DNA is removed and the complimentary strand is used to re-synthesize the damaged portion of DNA.

True

In generalized transduction, up to 90% of transducted DNA is not integrated into the recipient's chromosome, rather it is able to remain intact temporarily to be expressed.

True

Successful mismatch repair depends upon the ability of enzymes to distinguish between old and new replicated DNA strands.

True

Transposons frequently move between plasmids to transfer antibiotic resistance genes.

True

True or False Frameshift mutations are very deleterious and often result in synthesis of nonfunctional proteins.

True

True or False If a mutation renders a promotional sequence nonfunctional, the mutant will be unable to synthesize the product, even though the coding region is normal.

True

True or False Missense mutations play an important role in providing variability to drive evolution because they are not lethal and remain in the gene pool.

True

UV radiation can be used to induce lysogenic bacteriophage into a lytic cycle.

True

When an Hfr strain participates in conjugation, bacterial genes are frequently transferred to the recipient.

True (complete copy of factor F is usually not delivered)

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

all of the above

A change in the nucleotide sequence of a codon that does not change the amino acid encoded by that codon is called a

silent mutation