Microbiology - Chapter 10

[ch 10] Term for the direct transfer of DNA from a living donor bacterium to a recipient bacterium.

• transduction
• conjugation
• transformation
• transfection
• electroporation

conjugation

[ch 10] Compared to the eukaryotic genome, the bacterial genome:

• is more complex.
• is diploid in number.
• is difficult to manipulate.
• contains genes that are usually present in only one copy.
• contains only a small percent of DNA that encodes for functional proteins.

contains genes that are usually present in only one copy.

[ch 10] A bacterium which cannot synthesize all organic molecules needed for its growth is known as a/an:

• auxotroph
• heterotroph
• prototroph
• autotroph
• organotroph

auxotroph

[ch 10] What is an organism’s complete collection of alleles called?

• prototype
• genotype
• phenotype
• histotype
• wild-type

genotype

[ch 10] Suppose a mutant strain of Escherichia coli K12 contains a mutation in the trpE gene and is no longer able to make tryptophan. What is this mutant called?

• A phenotroph.
• An autotroph.
• A lithotroph.
• An auxotroph.
• A prototroph.

An auxotroph.

[ch 10] Bacteriophages vary in their ability to infect different strains of bacteria. This is because some bacteria contain _ __ that cut the phage DNA at certain sequences after it enters the cell. These enzymes can also be used for direct cloning of genes into plasmids.

• general nucleases
• DNA helicases
• DNA gyrases
• DNA topoisomerases
• restriction endonucleases

restriction endonucleases

[ch 10] Term for the uptake of extracellular DNA into a bacterial cell and incorporation into its genome.

• transfection
• transduction
• transformation
• reversion
• conjugation

transformation

[ch 10] Term for cells that can naturally take up extracellular DNA.

• competent
• primed
• conjugant
• susceptible
• porous

competent

[ch 10] Term for the transfer of donor DNA to a recipient bacterium via a bacteriophage.

• transfection
• lytic infection
• transduction
• transformation
• conjugation

transduction

[ch 10] Incorporation of foreign DNA into a host cell’s chromosome involving sequence similarity is called

• replica plating
• phenotypic selection
• cloning
• non-homologous recombination
• homologous recombination

homologous recombination

[ch 10] Bacterial genomes contain long stretches of noncoding DNA.

True or False

False

[ch 10] All bacterial genomes consist of a single, circular chromosome plus any plasmids which may be resent in the cell.

True or False

False

[ch 10] Mutations in bacterial cells that become evident after exposure to UV light were likely pre-existing in those cells.

True or False

True

[ch 10] Restriction enzymes that produce DNA fragments with blunt ends are not useful for generating recombinant molecules

True or False

False

[ch 10] An E. coli prototroph is able to grow on defined media without supplementation. However, a strain that is defined as met- pro+

• will only grow on media supplemented with proline.
• will only grow if the media has been supplemented with both methionine and proline.
• will only grow on media supplemented with methionine.
• will also grow on defined media with no supplementation.

will only grow on media supplemented with methionine.

[ch 10] A vector that can accommodate cloned fragments up to 50kb in size and be delivered with high efficiency into E. coli cells is

• a lambda phage vector
• pBR322
• a shuttle vector
• a cosmid vector

a shuttle vector

[ch 10] A wild type strain is

• a strain that possesses typical or representative characteristics of the species.
• a strain found naturally occurring in the environment.
• a mutated strain that grows very quickly under standard laboratory conditions.
• a strain created in the laboratory.

a strain that possesses typical or representative characteristics of the species.

[ch 10] The lambda phage genome is circular with 7 EcoRI restriction sites. When digested and separated on an agarose gel, how many bands (restriction fragments) should appear?

• 1
• 6
• 7
• 8

7

[ch 10] A property common to all restriction sites is:

• the presence of palindromic sequences that yield sticky ends that are complementary.
• they are DNA sequences 6 base pairs in length.
• they designate where both strands of the DNA double helix should be cut by restriction enzymes.
• all of these choices.

they designate where both strands of the DNA double helix should be cut by restriction enzymes.

[ch 10] Which horizontal gene transfer mechanism was used to engineer bacteria that may potentially protect against HIV infection?

• Conjugation
• Transformation
• Transduction
• Transposition

Transduction

[ch 10] Which horizontal gene transfer event does the donor cell survive?

• Transformation
• Conjugation
• Transduction

Conjugation

[ch 10] Bacterial genomes include the chromosomal DNA and any plasmid DNA present inside the cell.

True or False

True

[ch 10] Bacterial genomes consist of a single, circular chromosome.

True or False

False

[ch 10] Restriction enzymes that yield short regions of single stranded DNA (sticky ends) are more reliable for generating recombinant molecules in predictable ways compared to those that generate blunt ends (no sticky ends).

True or False

True

[ch 10] A cosmid is a hybrid plasmid/phage vector that combines beneficial cloning properties of both plasmids and phages.

True or False

True

[ch 10] Transformation involves the uptake of free pieces of external DNA while conjugation involves the transfer of specific pieces of DNA through cell-to-cell contact.

True or False

True

[ch 10] Naturally competent bacteria are able to take up DNA from the environment via

• specialized receptor and transport systems.
• directed endocytosis.
• influx pumps.
• simple diffusion of the DNA across the cell membrane.

specialized receptor and transport systems.

[ch 10] Which of the following is true about bacterial plasmids?

• One copy per cell.
• Replicate independent of the chromosome.
• Are linear, double-stranded DNA segments.
• Contain multiple origins of replication.

Replicate independent of the chromosome.

[ch 10] The difference between F+ and F- cells is

• F+ cells can become F-, but F- cells cannot become F+.
• F+ cells contain the fertility plasmid and are able to initiate conjugation while F- cells do not have the fertility plasmid and cannot initiate conjugation.
• F+ cells are able to conjugate only with F- cells, and F- cells are able to conjugate only with F+ cells.
• F+ are able to conjugate with only F+ cells, and F- cells are able to conjugate only with other F- cells.

F+ cells contain the fertility plasmid and are able to intiate conjugation while F- cells do not have the fertility plasmid and cannot initiate conjugation.

[ch 10] Replica plating or patching colonies in grid patterns onto test plates is a useful method for

• isolating auxotrophic mutants.
• identifying phenotypic variants.
• isolating wildtype strains of bacteria.
• identifying prototrophic mutants.

isolating auxotrophic mutants.

[ch 10] Naturally competent bacteria require _.

• DNA receptor proteins
• RNA receptor proteins
• DNA translocation proteins
• DNA receptor proteins and DNA translocation proteins

DNA receptor proteins and DNA translocation proteins

[ch 10] A piece of DNA is brought into a host cell. However, its sequence does not align or match with sequence on the genome. The bacteria then undergoes replication. What is likely to happen to this new piece of DNA?

• The piece of DNA will undergo homologous recombination and be maintained and found in the genome of the bacterium's offspring.
• The piece of DNA will undergo homologous recombination but will not be maintained and found in the genome of the bacterium's offspring.
• The piece of DNA will not undergo homologous recombination but will be maintained and found in the genome of the bacterium's offspring.
• The piece of DNA will not undergo homologous recombination and will not be maintained and found in the genome of the bacterium's offspring.

The piece of DNA will not undergo homologous recombination and will not be maintained and found in the genome of the bacterium's offspring.

[ch 10] Conjugation involves a special structure called a ____ which allows exchange of genetic material between a donor cell and a recipient cell.
• plasmid
• fimbriae
• sex pilus
• endospore

sex pilus

[ch 10] Of the following F- recipients of conjugation, what cells are likely to be capable of further conjugation with other bacteria after this round of conjugation occurs?

• F+ to F-
• Hfr to F-
• F' to F-
• F+ to F- and F' to F-
• All of these are correct.

F+ to F- and F' to F-

[ch 10] What forms of conjugation allow for the transfer of genomic material from the donor cell?

• F+ to F-
• Hfr to F-
• F' to F-
• Hfr to F- and F' to F-
• All of these are correct.

Hfr to F- and F' to F-

[ch 10] _ is responsible for cutting transposable elements out of a genome and then pasting it back into the genome.

• IR
• Resolvase
• Transposase
• None of these are correct

Transposase

[ch 10] You identify a site in the bacterial genome that contains only insertion sequences. What does this mean for transposition?

• This area is only capable of non-replicative transportation.
• This area is only capable of replicative transposition.
• This area is capable of non-replicative and replicative transposition.

This area is only capable of non-replicative transportation.

[ch 10] Viruses help transfer DNA between bacteria using a process called _.

• phaging
• transduction
• transformation
• genetic recombination

transduction

[ch 10] Transducting particles inject genetic material into new recipient cells that no longer contains _ resulting in the end of the page replication cycle.

• proteins
• RNA
• phage DNA
• plasmids

phage DNA

[ch 10] What is true of transduction?

• Bacteria must interact directly with other bacteria for transduction to occur.
• Bacterial DNA must be shredded for transduction to occur.
• Viruses must undergo replication in a host cell before transduction can occur.
• Bacterial DNA must be shredded for transduction to occur and viruses must undergo replication in a host cell before transduction can occur.
• All of these statements are true.

Bacterial DNA must be shredded for transduction to occur and viruses must undergo replication in a host cell before transduction can occur.