Question 1

Viruses that cause acute infection result in productive infections.

Accepted Answer

A) True 
 B)False

Question 2

Transmission of plant viruses by insects can occur from

Accepted Answer

A)  viruses associated with insect mouth parts. 
B)  viruses circulating but not multiplying in the insect's body. 
C)  viruses that multiply within the body of the insect. 
D)  All of the above 
A)  viruses associated with insect mouth parts. 
B)  viruses circulating but not multiplying in the insect's body. 
C)  viruses that multiply within the body of the insect. 
D)  All of the above

Question 3

In addition to lysis, animal viruses may exit the host cell by

Accepted Answer

A)  extrusion. 
B)  budding. 
C)  fission. 
D)  fusion. 
A)  extrusion. 
B)  budding. 
C)  fission. 
D)  fusion.

Question 4

Viroids characteristically are composed of

Accepted Answer

A)  ssRNA. 
B)  dsRNA. 
C)  ssDNA. 
D)  dsDNA. 
A)  ssRNA. 
B)  dsRNA. 
C)  ssDNA. 
D)  dsDNA.

Question 5

Enveloped viruses

Accepted Answer

A)  just require a stamp. 
B)  have an outer lipid bilayer membrane containing various proteins. 
C)  are surrounded by an additional layer of carbohydrate. 
D)  envelope a cell. 
A)  just require a stamp. 
B)  have an outer lipid bilayer membrane containing various proteins. 
C)  are surrounded by an additional layer of carbohydrate. 
D)  envelope a cell.

Question 6

An infection in which the virus is continually present in the body is referred to as

Accepted Answer

A)  acute. 
B)  balanced. 
C)  determinant. 
D)  persistent. 
A)  acute. 
B)  balanced. 
C)  determinant. 
D)  persistent.

Question 7

Crystallization of Tobacco Mosaic Virus was accomplished by

Accepted Answer

A)  Berkley. 
B)  Stanley. 
C)  Iwanowsky. 
D)  Twort. 
A)  Berkley. 
B)  Stanley. 
C)  Iwanowsky. 
D)  Twort.

Question 8

Why do animal viruses have envelopes and phages rarely do?

Accepted Answer

A)  Since bacteria don't have cell membranes, the bacterial viruses (phages) don't pick them up when they leave the target cells. 
B)  Phages acquire an outer surrounding that is a part of the cell wall of the bacterium they were created in, rather than an outer surrounding of plasma membrane. 
C)  Animal viruses will often utilize the envelope in order to fuse with the plasma membrane of a new target cell, gaining entry into the cytoplasm. 
D)  Animal viruses build the envelope inside of the target cell as they are being replicated, but before the cell breaks open and releases them into the extracellular environment. The envelope is a remnant of this building process. 
A)  Since bacteria don't have cell membranes, the bacterial viruses (phages) don't pick them up when they leave the target cells. 
B)  Phages acquire an outer surrounding that is a part of the cell wall of the bacterium they were created in, rather than an outer surrounding of plasma membrane. 
C)  Animal viruses will often utilize the envelope in order to fuse with the plasma membrane of a new target cell, gaining entry into the cytoplasm. 
D)  Animal viruses build the envelope inside of the target cell as they are being replicated, but before the cell breaks open and releases them into the extracellular environment. The envelope is a remnant of this building process.

Question 9

Viruses may not be cultivated in

Accepted Answer

A)  live organisms. 
B)  embryonated chicken eggs. 
C)  tissue culture. 
D)  blood agar. 
A)  live organisms. 
B)  embryonated chicken eggs. 
C)  tissue culture. 
D)  blood agar.

Question 10

A virion is a(n)

Accepted Answer

A)  pathogenic virus. 
B)  subviral particle. 
C)  complete, extracellular virus particle. 
D)  enveloped virus particle. 
A)  pathogenic virus. 
B)  subviral particle. 
C)  complete, extracellular virus particle. 
D)  enveloped virus particle.

Question 11

A virion is composed of

Accepted Answer

A)  lipid, protein, and either RNA or DNA. 
B)  protein and either RNA or DNA. 
C)  protein and both, RNA and DNA. 
D)  protein, either RNA or DNA, and possibly lipid. 
A)  lipid, protein, and either RNA or DNA. 
B)  protein and either RNA or DNA. 
C)  protein and both, RNA and DNA. 
D)  protein, either RNA or DNA, and possibly lipid.

Question 12

The filamentous phages all contain

Accepted Answer

A)  single-stranded DNA. 
B)  double-stranded DNA. 
C)  single-stranded RNA. 
D)  double-stranded RNA. 
A)  single-stranded DNA. 
B)  double-stranded DNA. 
C)  single-stranded RNA. 
D)  double-stranded RNA.

Question 13

Filamentous phage

Accepted Answer

A)  only infect E. coli lacking pili 
B)  only infect E. coli lacking pili. 
C)  infect E. coli regardless of the presence of pili. 
D)  do not infect 
A)  only infect E. coli lacking pili 
B)  only infect E. coli lacking pili. 
C)  infect E. coli regardless of the presence of pili. 
D)  do not infect

Question 14

The host range of a virus depends on the presence of host receptor molecules.

Accepted Answer

A) True 
 B)False

Question 15

Cells taken from a tumor

Accepted Answer

A)  may be used to grow viruses. 
B)  can be cultivated in vitro indefinitely. 
C)  may be used to grow bacteriophages. 
D)  divide 50 times and then die. 
E)  may be used to grow viruses AND can be cultivated in vitro indefinitely. 
A)  may be used to grow viruses. 
B)  can be cultivated in vitro indefinitely. 
C)  may be used to grow bacteriophages. 
D)  divide 50 times and then die. 
E)  may be used to grow viruses AND can be cultivated in vitro indefinitely.

Question 16

Normal tissue taken from animals and prepared immediately as media for viral growth is termed a(n)

Accepted Answer

A)  advantageous group. 
B)  monolayer culture. 
C)  plaque. 
D)  primary culture. 
A)  advantageous group. 
B)  monolayer culture. 
C)  plaque. 
D)  primary culture.

Question 17

Prions affect the

Accepted Answer

A)  respiratory system. 
B)  gastrointestinal tract. 
C)  nervous system. 
D)  lymphatic system. 
A)  respiratory system. 
B)  gastrointestinal tract. 
C)  nervous system. 
D)  lymphatic system.

Question 18

In the case of T-even phages, the burst size is about

Accepted Answer

A)  1 per host cell. 
B)  5 per host cell. 
C)  200 per host cell. 
D)  1000 per host cell. 
A)  1 per host cell. 
B)  5 per host cell. 
C)  200 per host cell. 
D)  1000 per host cell.

Question 19

Bacteriophage, unlike animal viruses, often have special viral-specific enzymes carried in the capsid which enter the host cell at the same time as the nucleic acid.

Accepted Answer

A) True 
 B)False

Question 20

A mutation in E. coli results in the loss of both restriction endonucleases and modification enzymes. Would you expect any difference in the frequency of gene transfer via transduction FROM Salmonella INTO this E. coli strain?

Accepted Answer

A)  No-since the Salmonella strain is normal, the rate of production of transducing virus particles would still be the same, resulting in the same frequency of gene transfer. 
B)  Yes-the loss of the restriction endonucleases would leave the recipient 
C)  Yes-the loss of the modification enzymes would leave the recipient 
D)  No-transduction efficiency isn't affected by either restriction endonucleases or modification enzymes, so there'd be no effect on the overall rate. 
E)  Yes-the loss of the restriction endonucleases would leave the recipient E. coli unable to break down 'invading' viral DNA from the transducing phage, AND the loss of the modification enzymes would leave the recipient E. coli unable to tag its own DNA as 'self,' leaving the viral DNA untagged and recognizable as 'foreign,' and targeted for destruction. Together, these would lead to higher rates of successful transduction. 
A)  No-since the Salmonella strain is normal, the rate of production of transducing virus particles would still be the same, resulting in the same frequency of gene transfer. 
B)  Yes-the loss of the restriction endonucleases would leave the recipient 
C)  Yes-the loss of the modification enzymes would leave the recipient 
D)  No-transduction efficiency isn't affected by either restriction endonucleases or modification enzymes, so there'd be no effect on the overall rate. 
E)  Yes-the loss of the restriction endonucleases would leave the recipient E. coli unable to break down 'invading' viral DNA from the transducing phage, AND the loss of the modification enzymes would leave the recipient E. coli unable to tag its own DNA as 'self,' leaving the viral DNA untagged and recognizable as 'foreign,' and targeted for destruction. Together, these would lead to higher rates of successful transduction.

Exam 13: Viruses, Viroids and Prions

Viruses that cause acute infection result in productive infections.

Transmission of plant viruses by insects can occur from

In addition to lysis, animal viruses may exit the host cell by

Viroids characteristically are composed of

Enveloped viruses

An infection in which the virus is continually present in the body is referred to as

Crystallization of Tobacco Mosaic Virus was accomplished by

Why do animal viruses have envelopes and phages rarely do?

Viruses may not be cultivated in

A virion is a(n)

A virion is composed of

The filamentous phages all contain

Filamentous phage

The host range of a virus depends on the presence of host receptor molecules.

Cells taken from a tumor

Normal tissue taken from animals and prepared immediately as media for viral growth is termed a(n)

Prions affect the

In the case of T-even phages, the burst size is about

Bacteriophage, unlike animal viruses, often have special viral-specific enzymes carried in the capsid which enter the host cell at the same time as the nucleic acid.

A mutation in E. coli results in the loss of both restriction endonucleases and modification enzymes. Would you expect any difference in the frequency of gene transfer via transduction FROM Salmonella INTO this E. coli strain?

Humans and the Microbial World

The Molecules of Life

Microscopy and Cell Structure

Dynamics of Prokaryotic Growth

Control of Microbial Growth

Metabolism: Fueling Cell Growth

The Blueprint of Life, From Dna to Protein

Bacterial Genetics

Biotechnology and Recombinant Dna

Identification and Classification of Prokaryotes

The Diversity of Prokaryotic Organisms

The Eukaryotic Members of the Microbial World

The Innate Immune Response

The Adaptive Immune Response

Host-Microbe Interactions

Immunologic Disorders

Applications of Immune Responses

Epidemiology

Antimicrobial Medications

Respiratory System Infections

Skin Infections

Wound Infections

Digestive System Infections

Genitourinary Infections

Nervous System Infections

Blood and Lymphatic Infections

Hiv Disease and Complications of Immunodeficiency

Microbial Ecology

Environmental Microbiology: Treatment of Water, Wastes, and Polluted Habitats

Food Microbiology

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