Chapter 7 Part B

The effects of a transposition event are equivalent to a(n) nonsense mutation. frameshift mutation. HFR conjugation. missense mutation. silent mutation.

Which type of transposon would contain a gene for transposase? Complex transposons Both simple and complex transposons Simple transposons Neither simple nor complex transposons; the transposase enzyme is coded independently by the cell.

How do complex transposons differ from simple transposons? Complex transposons code for additional genetic elements, such as antibiotic resistance genes; simple transposons only code for the transposase gene essential for the tranposon itself. Complex transposons code for transposase; simple transposons do not. Complex transposons are found in multiple locations in the target DNA; simple transposons are found only in one location.

Which of the following is capable of conjugation? bacteriophages F- cells F+ and Hfr cells competent cells

How does specialized transduction differ from regular lysogeny? The resulting bacteriophage from specialized transduction does not contain any viral DNA. The resulting bacteriophage from specialized transduction cannot infect a new host cell. The prophage is not excised during specialized transduction. The prophage in specialized transduction carries with it pieces of the host chromosomal DNA.

What happens to the packaged DNA of a specialized transduced phage when it infects a new recipient cell? The DNA begins to replicate without integrating into the host chromosome. The DNA is chewed up by enzymes found in the recipient cell. The host DNA integrates, with the prophage, into the new recipient chromosome.

How can specialized transduction contribute to the transfer of antibiotic resistance genes in a bacterial population? The phage causes the destruction of any antibiotic present during the specialized transduction process. The prophage takes an antibiotic resistance gene with it and is packaged with the newly synthesized viral DNA. The phage lyses the bacterium and releases resistance genes into the local environment, which can then be taken up by recipient cells.

Insertion sequences target which areas on a target DNA sequence? A gene coding for antibiotic resistance The gene that codes for transposase A unique inverted repeat sequence not found on the insertion sequence A sequence of nucleotides identical to the inverted repeat sequence found on the insertion sequence itself

What makes an insertion sequence different from other DNA sequences found in a cell? They contain inverted repeats. They can integrate into the cell genome. They are capable of effecting their own movement from one location to another on DNA.

If the gene that codes for transposase is mutated so that it no longer produces the fully functional enzyme, how will the insertion sequence be affected? The insertion sequence would lose its ability to effect its own movement. The insertion sequence would randomly insert itself into new locations in the DNA. Nothing; the transposase gene has no known role for mobilizing insertion sequences. The transposase enzyme would cut randomly in the host genome, effectively killing the cell.

How does replicative transposition differ from cut-and-paste transposition? Replicative transposition makes use of the enzyme transposase; cut-and-paste transposition does not. Replicative transposition is faster than cut-and-paste transposition. Replicative transposition results in the transposon being copied to a new location; in cut-and-paste transposition, the entire transposon moves to the new location. Replicative transposition integrates into the host genome; cut-and-paste transposition does not.

Frederick Griffith discovered conjugation. transposons. the lac operon. DNA. transformation.

Bacteriophages are important for which of the following processes? translation transduction transcription transformation

Transfer of DNA between bacterial cells by viruses is called (transformation/transduction/conjugation).

Transfer of random pieces of DNA mediated by phage is known as conjugation. specialized transduction. generalized transduction. transformation of competent cells. transposition.

Most bacteria have a natural ability to take up DNA from their environment. True False

In generalized transduction, viruses carry random DNA sequences from one cell to another. True False

How does an F+ cell differ from an Hfr cell? F+ cells have no plasmids. Hfr strains have the F plasmid integrated into the chromosome. Hfr cells cannot perform conjugation. Hfr strains can no longer reproduce.

Why does conjugation between an Hfr strain and an F- strain not result in two Hfr strains? Hfr strains lack fertility factor. The transferred genes typically recombine with the recipient chromosome. The cell membranes between the two strands never fuse together. Conjugation is typically disrupted before the fertility factor can be transferred.

Which of the following is a characteristic of an F+ cell? Ability to mate with an F- cell Presence of a fertility factor Ability to synthesize sex pili, presence of a fertility factor, and ability to mate with an F- cell. Ability to synthesize sex pili

What benefit does the F- strain receive from mating with an Hfr strain? It acquires new, potentially beneficial genes from the Hfr strain. It can now produce sex pili. It becomes an F+ cell. It picks up a fertility factor.

The horizontal transfer process known as transduction requires a plasmid. involves a mutagen. requires a pilus. involves a virus. requires a cell to be "competent."

What is a nosocomial infection? It is a nutritional deficiency aggravated by hospital food that is served cold. It is a hospital-acquired infection. It is a MRSA infection. It is an infection acquired by swimming in contaminated lake water.

What term is used to describe bacterial cells that can naturally take up DNA from their environment? electroporated cells auxotrophs Hfr cells competent cells

How can hospital personnel prevent the spread of resistant Enterococcus faecium throughout the hospital? Hospital staff should never serve raw fruit and salads to patients. Hospital personnel should wash their hands when entering and leaving a patient's room. Hospital staff should wear shoe covers for the duration of their shift. Hospital staff should wear masks when entering a patient's room.

Which of the following is NOT used by bacteria to acquire new genetic material? transformation crossing over transduction conjugation

What does MDR mean? map directed route multi-drug-resistant multi-directional radioactivity minimal drug resistance

What was the scientific result of Frederick Griffith's experiments with Streptococcus pneumoniae? He showed that strain R cells could easily take up capsules released by dead S cells. He showed that the DNA from strain R cells could transform strain S cells. He showed that strain R and strain S cells could be killed by heat. He showed that the DNA from strain S cells could transform strain R cells.

What must occur for bacterial conjugation to take place? The cells must come into contact with each other. One of the cells must be E. coli. The cells must transfer RNA. Each cell must contain a plasmid.

Which statement about conjugation is false? After conjugation, each cell involved has a copy of the shared DNA. E. coli is the model for bacterial conjugation. Conjugation is a process of bacterial reproduction.

what is transferred during bacterial conjugation? RNA A bacterial plasmid A bacterial chromosome A conjugation pilus

How is a complex transposon different from a simple transposon? Complex transposons have one very long insertion sequence. They always integrate in multiple copies into the host genome. Complex transposons code for different types of transposase. They have two simple transposons with another DNA sequence between them.

Why does a complex transposon often contain an extra piece of DNA between the two insertion elements? The insertion elements require a certain distance between them to function properly. It is often a gene that confers a survival advantage to the host, such as antibiotic resistance. It prevents degradation of the whole transposon.

How would you be able to determine if the Tn5 transposon you put into a bacterium integrated into the host genome? The cells would grow at a faster rate than without the transposon. If the Tn5 transposon integrated into the host genome, the cells would not be able to take in any new tranposons. The cells would become longer due to the extra DNA in them. If the Tn5 transposon integrated into the host genome, the cells would show resistance to the antibiotic kanamycin.

In conjugation, F+ cells serve as recipient cells. can transfer DNA only to other F+ cells. do not have conjugation pili. contain "jumping genes." contain an F plasmid.

A recombinant cell donates DNA into a new cell. is a cell that receives DNA from an outside source and incorporates it into its own. is the result of a cell dividing.

What is the hallmark of all horizontal gene transfers? Transfer of DNA between organisms of the same generation Transfer of DNA from parent to offspring The use of plasmids Transfer of DNA using a virus

Which of the following is an example of horizontal gene transfer in bacteria? Conjugation Transduction, conjugation, and transformation Transformation Conjugation and transformation Transduction

A mutation that causes production of a defective pilus in a bacterium will prevent __________. transduction translation transformation conjugation

Competent cells are cells that have the ability to produce capsules. are also considered "rough-strain" based on colony phenotype. are killed by heat. can take up DNA from their surrounding environment and integrate it into their own chromosomes by recombination.

Mice that are injected with only the R strain of Streptococcus pneumoniae stay healthy, because their immune systems can kill this strain easily. become sick for prolonged periods of time. are killed, because R strain cells are deadly.

What characteristic of the S strain allows it to evade the immune system of the mice? They are genetically engineered to be resistant to killing. They are naturally competent. They are resistant to heat. The cells have a capsule.

What most likely explains the recovery of live S strain cells from a mouse injected with heat-killed S strain mixed with live R strain cells? The R strain cells picked up the capsules from the S strain cells. The R strain picked up the S strain DNA, enabling it to produce a capsule. The S strain fused with the R strain, making it resistant. The S strain was revived by the presence of the host's immune system.

Which finding is most surprising from Griffith's experiments? S strain cells kill the mice. S strains are able to escape phagocytosis. S strain cells are isolated from the blood of mice infected with heat-killed S strains and live R strains. R strain cells fail to produce a capsule.

While studying a bacterial strain, a scientist notes a short DNA sequence between inverted repeats is present in both the chromosome and a plasmid within the cell. This sequence is most likely a(n) (phage/transposon/F plasmid).

What is the function of the conjugation pilus? It contains an F plasmid. It converts F- cells into F+ cells. It pulls the F+ and F- cells together. It carries the chromosome of F- cells.

What is required by an F- cell to become an F+ cell? F plasmid Conjugation pilus F+ chromosome An F- cell to be a recipient

What is the key difference between donor cells and recipient cells? An F plasmid Cell membranes A chromosome Size

What cellular macromolecule is the fertility factor comprised of? Protein Carbohydrate Nucleic acid Lipid

At which point does a recipient cell become an F+ cell?

What is unique about transduction compared to normal bacteriophage infection? Transduction transfers DNA from the chromosome of one cell to another. The bacteriophage takes fragments of the cell with it during transduction. The bacteriophage does not erupt from an infected cell during transduction.

How is generalized transduction different from specialized transduction? Only one specific host gene is transferred in both specialized transduction and generalized transduction. Generalized transduction is initiated during lytic cycle of a virulent bacteriophage; specialized transduction is initiated during the lysogenic cycle of a temperate bacteriophage. Specialized transduction uses animal viruses instead of bacteriophage. Generalized transduction is initiated by a lysogenic bacteriophage; specialized transduction is initiated by a lytic phage.

A transducing phage has a viral coat made of host proteins. contains fragments of the host chromosome instead of the viral genome. cannot infect new host cells. is a lysogenic bacteriophage.

When a transducing phage interacts with a new host cell, the DNA from the previous host can recombine with the new host chromosome. the new host cell will be lysed. it will cause the new cell to produce more transducing phage.