Exam 1 Chapter 7
True or false: Bacteriophages contain their own genetic material, which governs the traits of the phage. True false question.TrueFalse
True
During conjugation, the initial contact between the donor and recipient cell involves structures called sex ............. that are made by F+ strains.
sex pili
What is a competent cell? Multiple choice question. A bacterial cell that can take up foreign DNA A bacterial cell that can transfer its genetic material to other cells by conjugation A bacterial cell that can be infected by bacteriophages A bacterial cell that can grow on minimal medium
A bacterial cell that can take up foreign DNA
What is an episome? Multiple choice question. A plasmid that can be transferred through conjugation A plasmid that can integrate into a chromosome A mutated version of a plasmid A small chromosome
A plasmid that can integrate into a chromosome
What is a heteroduplex? Multiple choice question. A region of DNA containing one or more mismatches that must be repaired A structure that allows the exchange of DNA between two bacterial cells via conjugation A cell that contains two different alleles of a given gene
A region of DNA containing one or more mismatches that must be repaired
What is the F factor that is found in F+ donor strains of E. coli? Multiple choice question. A small circular segment of DNA that is separate from the circular chromosome An extra chromosome that is not found in other strains A gene found on the circular chromosome
A small circular segment of DNA that is separate from the circular chromosome
What is a bacteriophage? Multiple choice question. A bacterial cell that can take up foreign DNA from its environment A dead bacterial cell A virus that infects bacteria A type of growth medium for bacterial cells
A virus that infects bacteria
The length of the Hfr chromosome that is transferred to a recipient cell during conjugation is directly related to the ______. Multiple choice question. length of time allowed for conjugation to occur number of copies of the Hfr chromosome in the donor cell size of the two bacterial cells involved in the conjugation
length of time allowed for conjugation to occur
A Streptococcus pneumoniae cell may begin to express competence proteins if a nearby cell secretes the ...............- peptide.
competence stimulating
Place the events that occur during conjugation in the correct order.
1. Pili from an F+ cell make contact with an F- cell 2. A conjugation bridge forms between the two cells. 3. The F factor DNA is cut. 4. Single-stranded DNA and the relaxese protein from a nucleoprotein. 5. The nucleoprotein passes through the exporter complex. 6. Relaxase joins the ends of the ends of the donated DNA together to form a circular molecule.
A strain of E. coli that contains an F factor and can act as a conjugation donor is designated ,................ and a strain that lacks the F factor may be a recipient and is designated ...................
Blank 1: F+ Blank 2: F-
During transformation, a DNA fragment that has bound to a cell surface receptor is cut into smaller fragments by an extracellular ................... After the DNA has been taken up by the cell, it is incorporated into the bacterial chromosome by homologous. ..................
Blank 1: endonuclease Blank 2: recombination
During conjugation, the chromosome in the Hfr strain is first. ............... , then transferred into the F— cell, where it may ................. with the homologous region of the recipient cell's chromosome.
Blank 1: nicked Blank 2: recombine
The competence of a bacterial cell can be affected by environmental factors such as ionic conditions,.................. , and the availability of. ..................
Blank 1: temperature Blank 2: nutrients
How is conjugation stopped during an interrupted mating experiment? Multiple choice question. By exposing the bacterial cells to chemicals that damage DNA By using a blender to separate the bacterial cells By suddenly changing the temperature at which the cells are growing By exposing the bacterial cells to bacteriophages
By using a blender to separate the bacterial cells
What is the shape of the majority of plasmids? Multiple choice question. Circular Linear
Circular
Contains genes encoding proteins that kill other bacterial cells
Col-plasmid matches
Exporter
Complex of proteins that spans the membranes of the donor cell
Which type of genetic transfer requires direct physical contact between two living bacterial cells? Multiple choice question. Conjugation Transduction Transformation
Conjugation
Match each structure involved in conjugation with the correct function. Pilus
Contacts the recipient cell and draws the donor and recipient cell together Contacts the recipient cell and draws the donor and recipient cell together
Enables bacteria to digest an unusual substance
Degradative plasmid
Relaxase
Enzyme that rejoins the ends of the transferred DNA to form a circular molecule
In addition to their circular chromosome, strains of E. coli that can act as donors during conjugation contain a small circular segment of DNA called a(n) ................ factor
F, fertility, f+, f, or F+
True or false: An entire Hfr chromosome may be transferred to a recipient cell if conjugation is allowed to proceed for at least 30 minutes. True false question.TrueFalse
False
True or false: Most plasmids are linear. True false question.TrueFalse
False
True or false: Transformation, the uptake of foreign DNA by bacterial cells, does not occur in nature, but it is possible in genetically engineered bacterial strains.
False
Allows conjugation
Fertility plasmid
Conjugation bridge
Passageway for DNA transfer between the donor and recipient cell
What is required in order for genetic material to be transferred between two bacterial cells by conjugation? Multiple choice question. A bacteriophage that can infect both cells Physical contact between the two cells The death of one of the cells but not the other
Physical contact between the two cells
Confers resistance against antibiotics and other toxins
Resistance plasmid
What is genetic transfer? Multiple choice question. The rearrangement of genes within a chromosome The conversion of a mutant allele to a wild-type allele The transfer of genetic material between bacterial cells The mechanism that occurs during a cross over between two genes
The transfer of genetic material between bacterial cells
What is the function of the sex pili during conjugation? Multiple choice question. They cut the DNA of the F factor at the origin of transfer. They enable the DNA to be replicated in a rolling circular mechanism. They rejoin the ends of the linear DNA after it has been transferred. They make contact with recipient cells.
They make contact with recipient cells.
The functions of competence factors include ______. Multiple select question. binding to bacteriophages and facilitating their entry into a bacterial cell allowing DNA fragments to bind to the surface of a bacterial cell incorporating DNA into the bacterial chromosome aiding the uptake of DNA into the cytoplasm of a bacterial cell assembling into fibers that form sex pili
allowing DNA fragments to bind to the surface of a bacterial cell incorporating DNA into the bacterial chromosome aiding the uptake of DNA into the cytoplasm of a bacterial cell
A bacterial strain that cannot synthesize a particular nutrient and therefore requires that nutrient to be included in its growth medium is called a ....................
auxotroph
Bacteria that can take up DNA from the environment carry genes encoding proteins that aid DNA binding to the cell surface, uptake of DNA into the cytoplasm, and incorporation of foreign DNA into the bacterial chromosome. These proteins are called. ................... factors.
competence
A bacterial cell that is able to take up foreign DNA from its environment is called a(n) .............. cell.
competent
F factors carry genes that are necessary for the process of ..................
conjugation
A bacterial strain that is a leucine prototroph is a strain that ______. Multiple choice question. cannot survive when leucine is included in its growth medium requires leucine in its growth medium does not require leucine in its growth medium
does not require leucine in its growth medium
A plasmid that can integrate into a chromosome is called a(n). ............
episome
Any process in which one bacterium transfers genetic material to another bacterium is called ______. Multiple choice question. infection genetic transfer recombination competence
genetic transfer
A bacterium is typically. ................. for a particular gene, meaning that it only has one copy of the gene.
haploid
In order for a segment of transformed DNA that carries a lys+ gene to be incorporated into a lys— cell ______. Multiple choice question. homologous recombination must occur a bacteriophage must infect the recipient cell the recipient strain must be resistant to antibiotics
homologous recombination must occur
The transfer of genetic material to an organism that is not the offspring of the donor organism is referred to as ............. gene transfer.
horizontal gene transfer.
If conjugation occurs between the two cells shown in this figure, which gene will be transferred first? Multiple choice question. lac+ pro+
lac+
Infection of a bacterial cell with bacteriophage can lead to the production and assembly of new phages, which eventually cause the host cell to burst open. This is referred to as the. ...................... cycle.
lytic
A growth medium that contains only the essential nutrients required for the growth of a wild-type bacterial species is called a(n) ............... medium.
minimal
In a bacterial conjugation experiment, the unit used for genetic mapping is the ______
minute
The unit of measure that is used for the distance between two genes on a bacterial chromosome is the. .............
minute
Based on the time it takes for different genes to be transferred from an Hfr strain to an F— strain, one can deduce the .................. of genes along the bacterial chromosome.
order
To initiate conjugation, the F factor must be cut at a site called the. ..............of .........
origin transfer
In order to be replicated independently of the bacterial chromosome, a plasmid must have its own ................ of. ................
origin replication
After conjugation, a recipient cell may have a new combination of alleles if homologous. ................... occurred between the transferred Hfr chromosome and the original chromosome of the bacterial cell.
recombination
During conjugation, the protein complex that recognizes the origin of transfer in the F factor, cuts one of the strands, and then separates the two DNA strands is called the ...................
relaxosome
The competence-stimulating peptide of Streptococcus pneumoniae ______. Multiple choice question. forms a channel in the plasma membrane that allows the passage of ions and small molecules allows the cell that produces the protein to take up foreign DNA stimulates nearby cells to express competence proteins induces the formation of a sex pilus on a nearby cell
stimulates nearby cells to express competence proteins
During conjugation, the time that it takes for different genes to be transferred to a donor cell depends on ______. Multiple choice question. their size relative to one another. whether they are advantageous for the recipient cell. their order on the bacterial chromosome.
their order on the bacterial chromosome.
The linear order of genes on a bacterial chromosome can be deduced based on the. ................. it takes for different genes to be transferred to a recipient strain by conjugation.
time
An Hfr bacterial strain is very efficient at ______. Multiple choice question. producing new bacteriophages and releasing them into the environment transferring genes from its chromosome to F— strains taking up foreign DNA from the environment
transferring genes from its chromosome to F— strains
How long does it take for an entire Hfr chromosome to be transferred from an Hfr strain to an F- cell? Multiple choice question. 1.5 to 2 hours 4 to 6 hours 10 to 12 hours 10 to 15 minutes
1.5 to 2 hours
What is a plasmid? Multiple choice question. A DNA molecule that can exist independently of the bacterial chromosome A large circular chromosome found in bacteria A gene found in some bacteria that enables them to transfer DNA to other bacterial cells The location on the bacterial chromosome where DNA replication begins
A DNA molecule that can exist independently of the bacterial chromosome
Plasmids can be divided into several categories. Match each plasmid with the characteristic likely to be found in a bacterium that has the plasmid.
F factor: Found in a bacterial strain capable of conjugation R factor: Found in a bacterial strain that is resistant to an antibiotic Degradative plasmid: Found in a bacterial strain that can digest organic solvents such as toluene Col-plasmid: Found in a bacterial strain that kills other types of bacteria Virulence plasmid: Found in a bacterial strain that causes disease
What is the structure of a bacteriophage? Multiple choice question. Protein surrounded by a cell membrane Protein surrounded by a carbohydrate coat Genetic material surrounded by a cell membrane Genetic material surrounded by a protein coat
Genetic material surrounded by a protein coat
Which type of E. coli strain frequently transfers chromosomal genes to recipient bacterial cells? Multiple choice question. virulent F- Hfr F+
Hfr
Which type of strain does a bacterial cell become when an F factor integrates into its chromosome? Multiple choice question. bacteriophage virulent Hfr F-
Hfr
DNA from the bacterial chromosome may be transferred from one cell to another if a(n) .................. cell conjugates with an F— cell.
Hfr or F'
What event is required for genes on an Hfr chromosome to be transferred onto the recipient cell's chromosome? Multiple choice question. Infection with a bacteriophage Lysis of the recipient cell Homologous recombination DNA replication
Homologous recombination
What is nonhomologous recombination? Multiple choice question. Incorporation of DNA from a bacterial chromosome into a bacteriophage Incorporation of a DNA fragment at a random chromosomal location Exchange of DNA between two unrelated bacterial species
Incorporation of a DNA fragment at a random chromosomal location
What event leads to the formation of an Hfr strain? Multiple choice question. Exposure to high temperatures Uptake of foreign DNA from dead bacterial cells Infection of a bacterial cell with a bacteriophage Integration of an F factor into a bacterial chromosome
Integration of an F factor into a bacterial chromosome
What is the significance of a plasmid's origin of replication? Multiple choice question. It allows the plasmid to be maintained in a bacterial cell in the presence of an antibiotic. It allows the plasmid to be copied separately from the bacterial chromosome. It allows the plasmid to integrate into the bacterial chromosome.
It allows the plasmid to be copied separately from the bacterial chromosome.
What are the functions of the relaxosome in conjugation? Multiple select question. It recognizes the origin of transfer in the F factor. It joins the two ends of a single-stranded DNA molecule to form a circular molecule. It pumps nucleoproteins from a donor cell to a recipient cell. It separates the two strands of the F factor. It forms a passageway between the donor and recipient cells.
It recognizes the origin of transfer in the F factor. It separates the two strands of the F factor.
How do F+ and F- strains of E. coli differ from one another? Multiple choice question. Only F+ strains can be infected by bacteriophage. Only F- strains require a nutritional supplement in their growth media. Only F+ strains contain an F factor.
Only F+ strains contain an F factor.
If the two cells undergo conjugation, but only for a short period of time, what is the likely outcome? Multiple choice question. Only a short segment of the chromosome is transferred. The entire genome is transferred. The entire plasmid is transferred. The entire segment of the chromosome is transferred.
Only a short segment of the chromosome is transferred.
What is contained in a minimal medium? Multiple choice question. Only non-essential nutrients Both essential and non-essential nutrients No nutrients Only essential nutrients
Only essential nutrients
What two types of molecules are found in a nucleoprotein? Multiple select question. Lipid Carbohydrate Protein Nucleic acid
Protein Nucleic acid
Relaxosome
Protein complex that recognizes the origin of transfer
What DNA sequence in the F factor is recognized and cut to begin the process of conjugation? Multiple choice question. The origin of transfer The promoter The origin of replication The start codon
The origin of transfer
Carries genes that turn a bacterium into a pathogenic strain
Virulence plasmid
The genes that are carried on F factors are required for ______. Multiple choice question. conjugation transduction transformation
conjugation
During conjugation, the starting point and direction of DNA transfer are determined by a DNA sequence within the F factor called the ______. Multiple choice question. origin of transfer origin of replication high frequency recombinant insertion sequence
origin of transfer
A conjugation bridge is a ______. Multiple choice question. passageway for DNA transfer protein complex that pumps a nucleoprotein out of the donor cell protein complex that recognizes the origin of transfer complex made of DNA and protein
passageway for DNA transfer
A DNA molecule that can exist independently of the bacterial chromosome is called a(n) ______. Multiple choice question. episome competence factor pilus plasmid
plasmid
Bacteriophages are composed of genetic material that is surrounded by a coat made of. .................
protein
A bacterial strain that can synthesize a nutrient (e.g., methionine) and does not require that nutrient in its growth medium is called a(n). ......................
prototroph,
The traits of bacteriophages are governed by ______. Multiple choice question. their own genetic material the genetic material of the bacterial cells that they infect environmental factors, not by genetic material
their own genetic material
A scientist conducting an interrupted mating experiment can increase the amount of the Hfr chromosome that is transferred by ______. Multiple choice question. allowing conjugation to proceed for a longer period of time eliminating bacteriophages from the experiment increasing the number of Hfr cells in the experiment
allowing conjugation to proceed for a longer period of time
The passageway for DNA transfer between a donor cell and a recipient cell is called a conjugation ..............
conjugation bridge
For a given gene, a bacterial cell is usually ______. Multiple choice question. haploid diploid polyploid
haploid
During transformation, homologous recombination may create a region of DNA containing one or more base mismatches that must be repaired. This region is called the ______. Multiple choice question. heterozygote nonhomologous region heteroduplex heterochromatin
heteroduplex
During transformation, a functional gene may be replaced with a nonfunctional gene within the bacterial chromosome if the two copies of the gene align and exchange pieces through a process called. ...............
homologous recombination
In a conjugation experiment between between the two cells shown here, transfer of both the leu+ and thr+ genes could be monitored by growing the recipient cells on media ______. Multiple choice question. lacking both leucine and threonine containing both leucine and threonine lacking leucine, but containing threonine containing leucine, but lacking threonine
lacking both leucine and threonine
If conjugation occurs between these two cells, transfer of the strs and azis genes from the Hfr to the F- cell would be confirmed if the cells were ______. Multiple choice question. unable to grow in the presence of either streptomycin or azide able to grow in the presence of azide, but not in the presence of streptomycin able to grow in the presence of streptomycin and azide able to grow in the presence of streptomycin, but not in the presence of azide
unable to grow in the presence of either streptomycin or azide
What determines the starting point and direction of DNA transfer during conjugation involving an Hfr strain? Multiple choice question. The origin of replication of the bacterial chromosome The origin of replication of an excised F' factor The origin of transfer of the integrated F factor
The origin of transfer of the integrated F factor
When does conjugation result in the transfer of part of the bacterial chromosome to recipient cells? Multiple choice question. When two F- strains conjugate with one another When an Hfr strain conjugates with an F- strain When two Hfr strains conjugate with one another When an F+ strain conjugates with an F- strain
When an Hfr strain conjugates with an F- strain
What happens during the lytic cycle? Multiple choice question. The genetic material of a bacteriophage becomes integrated into the chromosome of an infected bacterial cell. The F factor is excised from a bacterial chromosome and transferred to a recipient cell, along with some bacterial genes. An infected bacterial cell synthesizes new bacteriophages and then bursts, releasing the phages.
An infected bacterial cell synthesizes new bacteriophages and then bursts, releasing the phages.
What is horizontal gene transfer? Multiple choice question. Transfer of DNA to a recipient that is not the offspring of the donor organism Incorporation of foreign DNA into a bacterial chromosome Transfer of two genes that are close to one another on the same chromosome Homologous recombination between a plasmid and a bacterial chromosome
Transfer of DNA to a recipient that is not the offspring of the donor organism
Which of the following statements about transformation is correct? Multiple choice question. Transformation is a natural process that has evolved in some species of bacteria. Transformation occurs only in bacteria that have been genetically engineered. Transformation is a natural process that occurs in some types of eukaryotic cells, but not in bacteria.
Transformation is a natural process that has evolved in some species of bacteria
The phenomenon in which a bacterial strain that is susceptible to a specific antibiotic becomes resistant to that antibiotic is called .................... antibiotic resistance.
acquired
Acquired antibiotic resistance is a phenomenon in which a(n) ______. Multiple choice question. bacterial strain that was previously susceptible to an antibiotic becomes resistant to it bacterial strain begins to produce an antibiotic that it was unable to produce previously antibiotic becomes effective against strains that were previously resistant to it
bacterial strain that was previously susceptible to an antibiotic becomes resistant to it
Arrange the steps involved in conjugation between an Hfr strain and an F— strain in the correct order starting at the top.
1. The Hfr chromosome is nicked at the origin of transfer 2. One strand of DNA from the Hfr chromosome begins to enter the F- cell. 3. DNA from the Hfr chromosome recombines with the homologous region of the recipient cell's chromosome.
What is an auxotroph? Multiple choice question. A bacterial strain that requires a certain nutrient to be supplemented in its growth medium A bacterial strain that cannot be infected by viruses A bacterial strain that can grow on minimal media that contains only essential nutrients
A bacterial strain that requires a certain nutrient to be supplemented in its growth medium
In an interrupted mating experiment, what genes will be transferred to the recipient cell first? Multiple choice question. Genes that are close to the origin of transfer Genes that are small Genes that are essential for survival Genes that have homologs in the recipient cell
Genes that are close to the origin of transfer
A virus that infects bacteria is called a(n). ....................
bacteriophage
The incorporation of a transformed DNA fragment into the bacterial chromosome at a random site is called ........................ recombination.
nonhomologous recombination.
A complex of DNA and protein is called a(n) ______. Multiple choice question. nucleoprotein ribosome competence factor conjugation factor
nucleoprotein
Environmental factors that can influence whether or not a bacterial cell is competent include ______. Multiple select question. nutrient availability the presence of bacteriophages whether or not a bacterial cell carries genes encoding competence factors ionic conditions temperature
nutrient availability ionic conditions temperature
