Question 1

Reverse transcriptase is a(n)

Accepted Answer

A)  RNA-dependent DNA polymerase. 
B)  DNA-dependent DNA polymerase. 
C)  RNA-dependent RNA polymerase. 
D)  DNA-dependent RNA polymerase. 
A)  RNA-dependent DNA polymerase. 
B)  DNA-dependent DNA polymerase. 
C)  RNA-dependent RNA polymerase. 
D)  DNA-dependent RNA polymerase.

Question 2

Regarding the viral membrane of an enveloped virus,the lipids are derived from the ________,and the proteins are encoded by ________.

Accepted Answer

A)  host's cell membrane / viral genes 
B)  virion / viral genes 
C)  host's cell membrane / host's genes 
D)  virion / host's genes 
A)  host's cell membrane / viral genes 
B)  virion / viral genes 
C)  host's cell membrane / host's genes 
D)  virion / host's genes

Question 3

RNA replicase is found in ALL viruses to allow the replication and transcription of viral RNA instead of host RNA.

Accepted Answer

A) True 
 B)False

Question 4

Bacteriophage have a ________ complex structure than animal viruses,because ________.

Accepted Answer

A)  more / bacteriophages must be coated by lipopolysaccharide to attach to bacterial cells 
B)  less / the bacteriophage does not have to penetrate the nucleus 
C)  more / the bacteriophage must penetrate the peptidoglycan cell wall 
D)  less / there prokaryotic cells have a simple structure compared to eukaryotic cells 
A)  more / bacteriophages must be coated by lipopolysaccharide to attach to bacterial cells 
B)  less / the bacteriophage does not have to penetrate the nucleus 
C)  more / the bacteriophage must penetrate the peptidoglycan cell wall 
D)  less / there prokaryotic cells have a simple structure compared to eukaryotic cells

Question 5

In E.coli,the adenine in the sequence GATC is methylated by the Dam enzyme.In the same cells a restriction endonuclease recognizes and cleaves dsDNA with GATC on either strand.Why does E.coli have these two enzymes?

Accepted Answer

A)  The enzymes cut the E. coli genome into pieces that bind to viral particles and inhibit viral replication. 
B)  The enzymes increase the rate of mutation and genome rearrangement, thus increasing the likelihood that E. coli cells will mutate and become resistant to viral infection. 
C)  The enzymes encourage lysogeny because the cleavage sites are recognized by viral integrases. 
D)  The enzymes protect E. coli from infection by preferentially degrading viral or other exogenous DNA that is not methylated. 
A)  The enzymes cut the E. coli genome into pieces that bind to viral particles and inhibit viral replication. 
B)  The enzymes increase the rate of mutation and genome rearrangement, thus increasing the likelihood that E. coli cells will mutate and become resistant to viral infection. 
C)  The enzymes encourage lysogeny because the cleavage sites are recognized by viral integrases. 
D)  The enzymes protect E. coli from infection by preferentially degrading viral or other exogenous DNA that is not methylated.

Question 6

Restriction is

Accepted Answer

A)  the viral process whereby a host's DNA ceases normal functioning. 
B)  the viral process whereby the virus prevents other viruses from entering the cell. 
C)  a general host mechanism to prevent the invasion of foreign nucleic acid. 
D)  a general host mechanism to prevent virus particles from further infective action. 
A)  the viral process whereby a host's DNA ceases normal functioning. 
B)  the viral process whereby the virus prevents other viruses from entering the cell. 
C)  a general host mechanism to prevent the invasion of foreign nucleic acid. 
D)  a general host mechanism to prevent virus particles from further infective action.

Question 7

The T4 phage protects its DNA from host restriction endonucleases by

Accepted Answer

A)  glucosylating cytosine bases in the T4 genome to prevent DNA cleavage. 
B)  methylating all four bases (A, T, C, 
C)  integrating the viral genome into the host genome where it will not be degraded. 
D)  circularizing the viral genome so that it will not be degraded. 
E)  in the T4 genome to prevent DNA cleavage. 
A)  glucosylating cytosine bases in the T4 genome to prevent DNA cleavage. 
B)  methylating all four bases (A, T, C, 
C)  integrating the viral genome into the host genome where it will not be degraded. 
D)  circularizing the viral genome so that it will not be degraded. 
E)  in the T4 genome to prevent DNA cleavage.

Question 8

When a virus enters a host cell in which it can replicate,the process is called a(n)

Accepted Answer

A)  insertion. 
B)  infection. 
C)  prophage. 
D)  excision. 
A)  insertion. 
B)  infection. 
C)  prophage. 
D)  excision.

Question 9

What are the consequences of a viral infection of an animal cell?

Accepted Answer

A)  rapid lysis or latent infections 
B)  lysogeny followed by eventual lysis 
C)  lysis or lysogeny 
D)  Outcomes vary from rapid lysis to persistent infections, latent infections, or cancer. 
A)  rapid lysis or latent infections 
B)  lysogeny followed by eventual lysis 
C)  lysis or lysogeny 
D)  Outcomes vary from rapid lysis to persistent infections, latent infections, or cancer.

Question 10

Which of the following enzymes would you expect to find in the virion of a retrovirus,but NOT in a bacteriophage?

Accepted Answer

A)  lysozyme 
B)  methylase 
C)  restriction enzymes 
D)  reverse transcriptase 
A)  lysozyme 
B)  methylase 
C)  restriction enzymes 
D)  reverse transcriptase

Question 11

Propose a unique target for a drug that would inhibit replication of retroviruses in humans.

Accepted Answer

Students could choose to discuss proteas

Question 12

Viruses variously depend on their host cell for parts of the viral replication and maturation process.Many viruses do however encode for some enzymes that facilitate certain steps or virus-specific processes for viral replication and maturation.Which cellular processes and enzymes do ALL viruses lack and must therefore ALWAYS be supplied by the host cell?

Accepted Answer

In general ALL currently described virus

Question 13

A prophage replicates

Accepted Answer

A)  along with its host while the lytic genes are expressed. 
B)  along with its host while the lytic genes are not expressed. 
C)  independently of its host while the lytic genes are expressed. 
D)  independently of its host while the lytic genes are not expressed. 
A)  along with its host while the lytic genes are expressed. 
B)  along with its host while the lytic genes are not expressed. 
C)  independently of its host while the lytic genes are expressed. 
D)  independently of its host while the lytic genes are not expressed.

Question 14

In the first few minutes after host cell infection,the virus undergoes an eclipse.

Accepted Answer

A) True 
 B)False

Question 15

For bacteriophages and animal viruses ________ is the step in the viral life cycle that determines host cell or tissue specificity.

Accepted Answer

A)  attachment 
B)  penetration 
C)  synthesis 
D)  assembly 
A)  attachment 
B)  penetration 
C)  synthesis 
D)  assembly

Question 16

Cellular receptors may be composed of

Accepted Answer

A)  proteins. 
B)  carbohydrates. 
C)  lipids. 
D)  combinations of proteins, carbohydrates, and/or lipids. 
A)  proteins. 
B)  carbohydrates. 
C)  lipids. 
D)  combinations of proteins, carbohydrates, and/or lipids.

Question 17

The consequence of an infection by a temperate bacteriophage is that the bacterial cell

Accepted Answer

A)  lyses before it gets a chance to divide. 
B)  never lyses but continues to divide and replicate both the virus and the cell. 
C)  divides faster at moderate temperatures. 
D)  may lyse before it divides or may continue to divide and replicate both the virus and the cell. 
A)  lyses before it gets a chance to divide. 
B)  never lyses but continues to divide and replicate both the virus and the cell. 
C)  divides faster at moderate temperatures. 
D)  may lyse before it divides or may continue to divide and replicate both the virus and the cell.

Question 18

Viral replication is

Accepted Answer

A)  independent of the host cell's DNA but dependent on the host cell's enzymes and metabolism. 
B)  independent of both the host cell's DNA and the host cell's enzymes and metabolism. 
C)  dependent on the host cell's DNA and RNA. 
D)  dependent on the host cell's DNA, RNA, enzymes, and metabolism. 
A)  independent of the host cell's DNA but dependent on the host cell's enzymes and metabolism. 
B)  independent of both the host cell's DNA and the host cell's enzymes and metabolism. 
C)  dependent on the host cell's DNA and RNA. 
D)  dependent on the host cell's DNA, RNA, enzymes, and metabolism.

Question 19

Viruses can redirect host metabolic functions.

Accepted Answer

A) True 
 B)False

Question 20

Influenza is an acute human viral disease that causes brief cellular damage followed by healing and complete clearing of the virus from the body.Hepatitis C is a chronic viral disease that causes slow destruction of tissue and persistent virions that are not completely cleared.Which of these diseases is more likely to be caused by lytic virus and which is caused by a lysogenic virus?

Accepted Answer

Persistent viral infections occur when t

Exam 8: Viruses and Virology

Reverse transcriptase is a(n)

Regarding the viral membrane of an enveloped virus,the lipids are derived from the ________,and the proteins are encoded by ________.

RNA replicase is found in ALL viruses to allow the replication and transcription of viral RNA instead of host RNA.

Bacteriophage have a ________ complex structure than animal viruses,because ________.

In E.coli,the adenine in the sequence GATC is methylated by the Dam enzyme.In the same cells a restriction endonuclease recognizes and cleaves dsDNA with GATC on either strand.Why does E.coli have these two enzymes?

Restriction is

The T4 phage protects its DNA from host restriction endonucleases by

When a virus enters a host cell in which it can replicate,the process is called a(n)

What are the consequences of a viral infection of an animal cell?

Which of the following enzymes would you expect to find in the virion of a retrovirus,but NOT in a bacteriophage?

Propose a unique target for a drug that would inhibit replication of retroviruses in humans.

A prophage replicates

In the first few minutes after host cell infection,the virus undergoes an eclipse.

For bacteriophages and animal viruses ________ is the step in the viral life cycle that determines host cell or tissue specificity.

Cellular receptors may be composed of

The consequence of an infection by a temperate bacteriophage is that the bacterial cell

Viral replication is

Viruses can redirect host metabolic functions.

Microorganisms and Microbiology

Microbial Cell Structure and Function

Microbial Metabolism

Molecular Biology

Microbial Growth and Control

Microbial Genomics

Metabolic Regulation

Viral Genomes and Diversity

Genetics of Bacteria and Archaea

Genetic Engineering and Biotechnology

Microbial Evolution and Systematics

Metabolic Diversity of Microorganisms

Functional Diversity of Bacteria

Diversity of Bacteria

Diversity of Archaea

Diversity of Eukaryotic Microorganisms

Methods in Microbial Ecology

Microbial Ecosystems

Nutrient Cycles

Microbiology of the Built Environment

Microbial Symbioses

Microbial Interactions With Humans

Immunity and Host Defense

Immune Mechanisms

Molecular Immunology

Diagnostic Microbiology

Epidemiology

Person-To-Person Bacterial and Viral Diseases

Vectorborne and Soilborne Bacterial and Viral Diseases

Water and Food As Vehicles of Bacterial Diseases

Eukaryotic Pathogens: Fungal and Parasitic Diseases

Filters

Regarding the viral membrane of an enveloped virus,the lipids are derived from the ,and the proteins are encoded by .

Bacteriophage have a complex structure than animal viruses,because .