Question 1

How did Davis demonstrate that bacterial cells must be in physical contact in order for genetic exchange to occur?

Accepted Answer

A)  He mixed together two bacteria strains with different nutritional requirements,and then added them to agar plates that lacked their required nutrients.
B)  When two bacterial strains with different nutritional requirements were combined in a tube and allowed to grow for several hours,they acquired the ability to grow without the addition of biotin.
C)  When two bacterial strains with different nutritional requirements were separated from each other by a selective filter,they did not acquire the ability to grow on agar plates that lacked their required nutrients.
D)  Only when enough pressure was applied to force bacteria from one side of a selective filter to another did they acquire the ability to grow without their required nutrients.
E)  Nutritional deficient strains only acquired the ability to grow without their required nutrients when the pore size of a selective filter was increased to allow bacteria to pass from one side to the other.F) B) and D)
G) None of the above

Question 2

You are working in the field with your favorite bacteria species,Bacterium BB.You carry out some experiments with Bacterium BB,and find that it can now degrade toluene and it is pathogenic! What happened?

Accepted Answer

A)  Bacterium BB acquired degradative and virulence plasmids by horizontal gene transfer
B)  Bacterium BB picked up fertility and Col-plasmids via conjugation
C)  Bacterium BB was exposed to a bacteriophage which is now in its lytic phase
D)  Bacterium BB was transformed with a resistance plasmid and a digestive plasmid
E)  Bacterium BB sexually reproduced with another strain of bacteria that had both toluene-degrading gene and virulence geneF) A) and B)
G) A) and E)

Question 3

Bacterial plasmids

Accepted Answer

A)  are essential for growth
B)  can provide genes that allow the bacteria to grow and thrive in the presence of potential toxins
C)  are essential for cellular respiration
D)  are artificially created by humans and are present in bacteria only because humans put them there
E)  are essential for chromosome replication and binary fissionF) A) and D)
G) A) and C)

Question 4

How is binary fission similar to the mitosis/cytokinesis?

Accepted Answer

A)  both are modes of sexual reproduction
B)  both occur only in eukaryotes
C)  both occur only in prokaryotes
D)  both involve replication of DNA and separation of DNA equally into two daughter cells
E)  both give rise to offspring that are genetically different from the parentF) B) and C)
G) A) and B)

Question 5

When a virus has a broad host range

Accepted Answer

A)  it does not require close contact to infect a new host
B)  it can infect many different cell types
C)  it can infect many different species
D)  the species that the virus can infect are spread over a large geographic distance,potentially causing pandemics
E)  it can infect many cell types or speciesF) D) and E)
G) None of the above

Question 6

Which of the following is not a part of the general viral reproductive cycle?

Accepted Answer

A)  viral recognition of host surface proteins
B)  genome entry into the cell and immediate expression of some viral genes
C)  viral proteins are synthesized
D)  reverse transcriptase converts RNA to DNA
E)  fully assembled viruses are releasedF) A) and D)
G) A) and B)

Question 7

Lederberg and Tatum's landmark experiment showed that gene transfer could occur between bacteria,by mixing two strains of bacteria.One strain of bacteria could not synthesize methionine or biotin,but was capable of synthesizing threonine and proline.The other strain was able to synthesize methionine and biotin,but was not capable of synthesizing threonine and proline.Only when these strains were mixed together would they grow on agar that lacked these compounds.What negative control would Lederberg and Tatum have used to ensure that their experiments were accurate?

Accepted Answer

A)  A bacteria that could synthesize methionine,biotin,threonine,and proline.
B)  A bacteria that could not synthesize methionine,biotin,threonine,or proline.
C)  An agar media that contained methionine,biotin,threonine,and proline.
D)  An agar medium that lacked methionine,biotin,threonin,proline,and other nutrients that all bacteria require to grow (e.g.glucose) .
E)  A plate that contained no bacteriaF) C) and D)
G) None of the above

Question 8

A pro- strain of bacteria,which has not been in contact with any other strains,develops the ability to produce the amino acid proline.What is the most likely mechanism of this mutant "rescue?"

Accepted Answer

A)  addition of the pro+ gene via transduction
B)  addition of the pro+ gene during conjugation
C)  removal of the pro- gene during excision
D)  addition of the pro+ gene via transformation
E)  correction of the pro- gene by reverse transcriptaseF) A) and D)
G) A) and E)

Question 9

Lederberg and Tatum's landmark experiment showed that gene transfer could occur between bacteria,by mixing two strains of bacteria.One strain of bacteria could not synthesize methionine or biotin,but was capable of synthesizing threonine and proline.The other strain was able to synthesize methionine and biotin,but was not capable of synthesizing threonine and proline.Only when these strains were mixed together would they grow on agar that lacked these compounds.What positive control would Lederberg and Tatum have used to ensure that their experiments were accurate?

Accepted Answer

A)  A bacteria that was not cable of synthesizing methionine,biotin,threonin or proline.
B)  A bacteria that was capable of synthesizing methionine,biotin,threonin and proline.
C)  An agar medium that contained methionine,biotin,threonin and proline.
D)  An agar medium that lacked methionine,biotin,threonin,proline,and other nutrients that all bacteria require to grow (e.g.glucose) .
E)  No positive control would be used in this experiment because there are already two different strains of bacteria being tested.F) A) and D)
G) D) and E)

Question 10

Bacterial cells always contain one copy of a circular chromosome.

Accepted Answer

A) True 
 B)False

Question 11

During HIV reproduction,spike glycoproteins

Accepted Answer

A)  do not enter the cell with the virus
B)  are released into the cytoplasm by cellular enzymes
C)  undergo a conformational change to inject viral contents into the host cell
D)  are assembled into the virus along with reverse transcriptase
E)  are embedded in the viral capsidF) A) and E)
G) A) and D)

Question 12

A __________ bacterial cell is able to take up DNA from the environment.

Accepted Answer

A)  competent
B)  virulent
C)  fertile
D)  high frequency
E)  transducedF) A) and D)
G) A) and E)

Question 13

The figure below represents a lineage of a bacterial strain.Upon further studies of this system,you learn that the phage that infects the blue smile bacteria has a very small host range,and cannot infect the red smile bacteria.In light of this new information,determine what is the most likely mechanism that induced a change in the phenotype of this lineage.

Accepted Answer

A)  Random mutation
B)  Conjugation
C)  Transformation
D)  Transduction
E)  LysogenyF) B) and E)
G) A) and B)

Question 14

The figure below represents a lineage of a bacterial strain.Study the figure and determine what is the most likely mechanism that induced a change in the phenotype of this lineage.

Accepted Answer

A)  Random mutation
B)  Conjugation
C)  Transduction
D)  Transformation
E)  LysogenyF) A) and E)
G) A) and D)

Question 15

You analyze two daughter cells of Bacteria A immediately after binary fission.Which of the following is ACCURATE about the daughter cells?

Accepted Answer

A)  Each will have about half the number of plasmids as the mother cell.
B)  They are members of the same colony.
C)  They have genetically identical chromosomes.
D)  They are members of the same colony and have genetically identical chromosomes.
E)  They are members of the same colony,will have genetically identical chromosomes,and each will have about half the number of plasmids as the mother cell.F) A) and D)
G) None of the above

Question 16

Plasmids replicate independently of the bacterial chromosome

Accepted Answer

A) True 
 B)False

Question 17

Plasmids can help bacteria grow faster.

Accepted Answer

A) True 
 B)False

Question 18

A particle that consists of nucleic acids surrounded by protein and requires a host organism to replicate is

Accepted Answer

A)  a prokaryote
B)  a eukaryote
C)  a plasmid
D)  a virus
E)  bacteriumF) A) and E)
G) A) and C)

Question 19

Viral genomes must always be excised from the bacterial chromosome before viral components can be produced.

Accepted Answer

A) True 
 B)False

Question 20

What mechanism is used by a bacterial cell to fit its DNA into the nucleoid region?

Accepted Answer

A)  the formation of loop domains
B)  supercoiling by topoisomerases
C)  tight wrapping around histones to form nucleosomes
D)  the formation of loop domains and supercoiling by topoisomerases
E)  the formation of loop domains,supercoiling by topoisomerases,and tight wrapping around histones to form nucleosomesF) A) and B)
G) B) and C)

Exam 15: Genetics of Viruses and Bacteria

When a virus has a broad host range

Correct Answer
verified

During HIV reproduction,spike glycoproteins

Correct Answer
verified

A particle that consists of nucleic acids surrounded by protein and requires a host organism to replicate is

Correct Answer
verified

How did Davis demonstrate that bacterial cells must be in physical contact in order for genetic exchange to occur?

Correct Answer
verified

What mechanism is used by a bacterial cell to fit its DNA into the nucleoid region?

Correct Answer
verified

Plasmids can help bacteria grow faster.

Correct Answer
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A pro- strain of bacteria,which has not been in contact with any other strains,develops the ability to produce the amino acid proline.What is the most likely mechanism of this mutant "rescue?"

Correct Answer
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Plasmids replicate independently of the bacterial chromosome

Correct Answer
verified

Correct Answer
verified

Bacterial cells always contain one copy of a circular chromosome.

Correct Answer
verified

How is binary fission similar to the mitosis/cytokinesis?

Correct Answer
verified

Correct Answer
verified

Bacterial plasmids

Correct Answer
verified

Viral genomes must always be excised from the bacterial chromosome before viral components can be produced.

Correct Answer
verified

You analyze two daughter cells of Bacteria A immediately after binary fission.Which of the following is ACCURATE about the daughter cells?

Correct Answer
verified

Which of the following is not a part of the general viral reproductive cycle?

Correct Answer
verified

A __________ bacterial cell is able to take up DNA from the environment.

Correct Answer
verified

Correct Answer
verified

You are working in the field with your favorite bacteria species,Bacterium BB.You carry out some experiments with Bacterium BB,and find that it can now degrade toluene and it is pathogenic! What happened?

Correct Answer
verified

The figure below represents a lineage of a bacterial strain.Study the figure and determine what is the most likely mechanism that induced a change in the phenotype of this lineage.

Correct Answer
verified

Exam 15: Genetics of Viruses and Bacteria

When a virus has a broad host range

Correct AnswerverifiedShow Answer

During HIV reproduction,spike glycoproteins

Correct AnswerverifiedShow Answer

A particle that consists of nucleic acids surrounded by protein and requires a host organism to replicate is

Correct AnswerverifiedShow Answer

How did Davis demonstrate that bacterial cells must be in physical contact in order for genetic exchange to occur?

Correct AnswerverifiedShow Answer

What mechanism is used by a bacterial cell to fit its DNA into the nucleoid region?

Correct AnswerverifiedShow Answer

Plasmids can help bacteria grow faster.

Correct AnswerverifiedShow Answer

A pro- strain of bacteria,which has not been in contact with any other strains,develops the ability to produce the amino acid proline.What is the most likely mechanism of this mutant "rescue?"

Correct AnswerverifiedShow Answer

Plasmids replicate independently of the bacterial chromosome

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Bacterial cells always contain one copy of a circular chromosome.

Correct AnswerverifiedShow Answer

How is binary fission similar to the mitosis/cytokinesis?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Bacterial plasmids

Correct AnswerverifiedShow Answer

Viral genomes must always be excised from the bacterial chromosome before viral components can be produced.

Correct AnswerverifiedShow Answer

You analyze two daughter cells of Bacteria A immediately after binary fission.Which of the following is ACCURATE about the daughter cells?

Correct AnswerverifiedShow Answer

Which of the following is not a part of the general viral reproductive cycle?

Correct AnswerverifiedShow Answer

A __________ bacterial cell is able to take up DNA from the environment.

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

You are working in the field with your favorite bacteria species,Bacterium BB.You carry out some experiments with Bacterium BB,and find that it can now degrade toluene and it is pathogenic! What happened?

Correct AnswerverifiedShow Answer

The figure below represents a lineage of a bacterial strain.Study the figure and determine what is the most likely mechanism that induced a change in the phenotype of this lineage.

Correct AnswerverifiedShow Answer

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