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