Question 1

Is antigenic shift alone likely to lead to influenza pandemics?

Accepted Answer

A)  Yes-ONLY antigenic shift can lead to the large-scale mixing of gene elements required to produce a pandemic flu strain. 
B)  No-ONLY antigenic DRIFT can lead to the large-scale mixing of gene elements required to produce a pandemic flu strain. 
C)  Perhaps-but it would most likely be a mixture of antigenic shift AND drift that would result in a pandemic strain. 
D)  No-antigenic SHIFT is responsible for changes in the hemagglutinin protein, while antigenic DRIFT is responsible for changes in the neuraminidase protein. You must have changes in both to lead to a pandemic strain. 
A)  Yes-ONLY antigenic shift can lead to the large-scale mixing of gene elements required to produce a pandemic flu strain. 
B)  No-ONLY antigenic DRIFT can lead to the large-scale mixing of gene elements required to produce a pandemic flu strain. 
C)  Perhaps-but it would most likely be a mixture of antigenic shift AND drift that would result in a pandemic strain. 
D)  No-antigenic SHIFT is responsible for changes in the hemagglutinin protein, while antigenic DRIFT is responsible for changes in the neuraminidase protein. You must have changes in both to lead to a pandemic strain.

Question 2

Genetic exchange in segmented viruses that allows a zoonotic virus to infect humans is termed

Accepted Answer

A)  antigenic shift. 
B)  hemagglutination. 
C)  genetic reassortment. 
D)  antigenic drift. 
A)  antigenic shift. 
B)  hemagglutination. 
C)  genetic reassortment. 
D)  antigenic drift.

Question 3

DNA is protected from restriction enzymes by being

Accepted Answer

A)  sequestered in a lysosome. 
B)  turned into RNA. 
C)  methylated. 
D)  made into double stranded RNA. 
A)  sequestered in a lysosome. 
B)  turned into RNA. 
C)  methylated. 
D)  made into double stranded RNA.

Question 4

Lysogenized cells

Accepted Answer

A)  are immune to any further infection by any virus. 
B)  are immune to infection by the same virus. 
C)  may have new properties. 
D)  respond to infection with the SOS response. 
E)  are immune to infection by the same virus AND may have new properties. 
A)  are immune to any further infection by any virus. 
B)  are immune to infection by the same virus. 
C)  may have new properties. 
D)  respond to infection with the SOS response. 
E)  are immune to infection by the same virus AND may have new properties.

Question 5

A key feature of all viral infections is the

Accepted Answer

A)  integration of viral DNA into host DNA. 
B)  disintegration of host DNA. 
C)  addition of a lipid membrane to the virus. 
D)  separation of viral nucleic acid from the capsid. 
A)  integration of viral DNA into host DNA. 
B)  disintegration of host DNA. 
C)  addition of a lipid membrane to the virus. 
D)  separation of viral nucleic acid from the capsid.

Question 6

The common species name of the virus is based on the

Accepted Answer

A)  presence or absence of a nuclear membrane. 
B)  type of nucleic acid it contains. 
C)  disease the virus causes. 
D)  geographic area it is found. 
A)  presence or absence of a nuclear membrane. 
B)  type of nucleic acid it contains. 
C)  disease the virus causes. 
D)  geographic area it is found.

Question 7

Bacteriophages and animal viruses

Accepted Answer

A)  both may enter a host cell by endocytosis. 
B)  both may enter a host cell by fusion. 
C)  both involve entry of the entire nucleocapsid. 
D)  differ because bacteriophages leave the capsid outside the cell, while animal virus entry involves the entry of the whole nucleocapsid. 
A)  both may enter a host cell by endocytosis. 
B)  both may enter a host cell by fusion. 
C)  both involve entry of the entire nucleocapsid. 
D)  differ because bacteriophages leave the capsid outside the cell, while animal virus entry involves the entry of the whole nucleocapsid.

Question 8

One of the most intensively studied virulent phages which infects

Accepted Answer

A)  T9. 
B)  T4. 
C)  beta. 
D)  gamma. 
E)  coli is 
A)  T9. 
B)  T4. 
C)  beta. 
D)  gamma. 
E)  coli is

Question 9

Plant viruses may be passed from generation to generation of an insect vector.

Accepted Answer

A) True 
 B)False

Question 10

Would ID50 and LD50 necessarily be the same for a given virus? Why or why not?

Accepted Answer

A)  Yes, because the number of viruses that infect 50% of a test population should also kill 50% of that test population. 
B)  No, because a virus may be highly infectious (very low ID50 value) but only marginally lethal (very high LD50 value). A prime example of this is the rhinovirus (common cold virus). 
C)  No, because very few viruses are lethal, yet many are highly infectious. The 2 values should ALWAYS be different. 
D)  Yes, because what we're actually describing here is infection/killing of individual CELLS, not of entire organisms. If a cell is infected, it will always be killed. 
A)  Yes, because the number of viruses that infect 50% of a test population should also kill 50% of that test population. 
B)  No, because a virus may be highly infectious (very low ID50 value) but only marginally lethal (very high LD50 value). A prime example of this is the rhinovirus (common cold virus). 
C)  No, because very few viruses are lethal, yet many are highly infectious. The 2 values should ALWAYS be different. 
D)  Yes, because what we're actually describing here is infection/killing of individual CELLS, not of entire organisms. If a cell is infected, it will always be killed.

Question 11

What part of the attached bacteriophage enters through the host cell wall?

Accepted Answer

A)  the entire virus 
B)  only the enzymes necessary for replication 
C)  the nucleic acid 
D)  the nucleic acid and capsid 
E)  the capsid only 
A)  the entire virus 
B)  only the enzymes necessary for replication 
C)  the nucleic acid 
D)  the nucleic acid and capsid 
E)  the capsid only

Question 12

In the region of budding, the inside of the plasma membrane becomes coated with

Accepted Answer

A)  enzymes. 
B)  carbohydrates. 
C)  steroids. 
D)  matrix proteins. 
A)  enzymes. 
B)  carbohydrates. 
C)  steroids. 
D)  matrix proteins.

Question 13

The bacterial viruses that are released by a process termed extrusion are called

Accepted Answer

A)  lysogenic viruses. 
B)  temperate phages. 
C)  filamentous phages. 
D)  lambda viruses. 
A)  lysogenic viruses. 
B)  temperate phages. 
C)  filamentous phages. 
D)  lambda viruses.

Question 14

Viruses

Accepted Answer

A)  probably keep the numbers of bacteria in check. 
B)  have no effect on the number of bacteria. 
C)  increase the number of bacteria. 
D)  are active in passing DNA from one bacterium to another. 
E)  probably keep the numbers of bacteria in check AND are active in passing DNA from one bacterium to another. 
A)  probably keep the numbers of bacteria in check. 
B)  have no effect on the number of bacteria. 
C)  increase the number of bacteria. 
D)  are active in passing DNA from one bacterium to another. 
E)  probably keep the numbers of bacteria in check AND are active in passing DNA from one bacterium to another.

Question 15

The family to which the Rhinovirus belongs is the

Accepted Answer

A)  Picornaviridae. 
B)  Enterovirus. 
C)  Enteroviridae. 
D)  Picornavirus. 
A)  Picornaviridae. 
B)  Enterovirus. 
C)  Enteroviridae. 
D)  Picornavirus.

Exam 13: Viruses, Viroids and Prions

Is antigenic shift alone likely to lead to influenza pandemics?

Genetic exchange in segmented viruses that allows a zoonotic virus to infect humans is termed

DNA is protected from restriction enzymes by being

Lysogenized cells

A key feature of all viral infections is the

The common species name of the virus is based on the

Bacteriophages and animal viruses

One of the most intensively studied virulent phages which infects

Plant viruses may be passed from generation to generation of an insect vector.

Would ID50 and LD50 necessarily be the same for a given virus? Why or why not?

What part of the attached bacteriophage enters through the host cell wall?

In the region of budding, the inside of the plasma membrane becomes coated with

The bacterial viruses that are released by a process termed extrusion are called

Viruses

The family to which the Rhinovirus belongs is the

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

Filters

Would ID₅₀ and LD₅₀ necessarily be the same for a given virus? Why or why not?