Question 1

The "hygiene hypothesis" proposes that

Accepted Answer

A)  lack of exposure to microbes can promote development of allergies. 
B)  cleanliness truly is next to godliness. 
C)  hand washing is the best preventative measure against infection. 
D)  the immune system develops best in a clean environment. 
A)  lack of exposure to microbes can promote development of allergies. 
B)  cleanliness truly is next to godliness. 
C)  hand washing is the best preventative measure against infection. 
D)  the immune system develops best in a clean environment.

Question 2

The microorganisms that are regularly found in or on the body, yet do no apparent harm are called

Accepted Answer

A)  abnormal flora. 
B)  transient flora. 
C)  variant flora. 
D)  normal flora. 
A)  abnormal flora. 
B)  transient flora. 
C)  variant flora. 
D)  normal flora.

Question 3

Why is it a good strategy for a microbe to adhere to a receptor that plays a critical function for a host cell?

Accepted Answer

A)  It ISN'T a good strategy-host cells could shift to a backup receptor and shut down production of the main receptor, preventing infection. 
B)  If it's a receptor the cell MUST use, it doesn't have a backup system in place to switch to-so, even though it makes it susceptible to infection, it HAS to put that target out there. This benefits the microbe. 
C)  Microbes want to evade detection and elimination by the immune system-the closer they can adhere to host cells, the less likely they are to trigger destructive immune responses. This would be similar to using a hostage as a shield in a police-standoff situation. 
D)  It ISN'T a good strategy-by binding to receptors, microbes will be phagocytosed by cells and destroyed within them. 
A)  It ISN'T a good strategy-host cells could shift to a backup receptor and shut down production of the main receptor, preventing infection. 
B)  If it's a receptor the cell MUST use, it doesn't have a backup system in place to switch to-so, even though it makes it susceptible to infection, it HAS to put that target out there. This benefits the microbe. 
C)  Microbes want to evade detection and elimination by the immune system-the closer they can adhere to host cells, the less likely they are to trigger destructive immune responses. This would be similar to using a hostage as a shield in a police-standoff situation. 
D)  It ISN'T a good strategy-by binding to receptors, microbes will be phagocytosed by cells and destroyed within them.

Question 4

Bacteria may survive phagocytosis by

Accepted Answer

A)  preventing fusion of the lysosome with the phagosome. 
B)  lysing the phagosome. 
C)  producing comet tails. 
D)  preventing fusion of two phagosomes. 
E)  preventing fusion of the lysosome with the phagosome AND lysing the phagosome. 
A)  preventing fusion of the lysosome with the phagosome. 
B)  lysing the phagosome. 
C)  producing comet tails. 
D)  preventing fusion of two phagosomes. 
E)  preventing fusion of the lysosome with the phagosome AND lysing the phagosome.

Question 5

A relationship in which one partner benefits and the other is unaffected is termed

Accepted Answer

A)  commensalism. 
B)  parasitism. 
C)  independence. 
D)  mutualism. 
A)  commensalism. 
B)  parasitism. 
C)  independence. 
D)  mutualism.

Question 6

Avirulent organisms are

Accepted Answer

A)  more likely to cause disease. 
B)  more likely to cause severe disease. 
C)  unable to cause disease. 
D)  pathogenic. 
A)  more likely to cause disease. 
B)  more likely to cause severe disease. 
C)  unable to cause disease. 
D)  pathogenic.

Question 7

Infection always leads to disease.

Accepted Answer

A) True 
 B)False

Question 8

The most successful parasites are the ones that live in harmony with their hosts.

Accepted Answer

A) True 
 B)False

Question 9

Which of the following is NOT a likely reason why diseases caused by opportunists are becoming more frequent in the US population?

Accepted Answer

A)  HIV individuals (with impaired immune systems) survive longer due to more effective therapies-but this allows them a longer period of time to be infected by opportunists. 
B)  Individuals in the US are living longer than ever before-but they're living with a number of chronic health issues that can impair the immune system. This leads to a greater likelihood of opportunistic infections. 
C)  Cancer treatments have improved significantly in the last 30 years-but they often suppress the immune system. This leads to a greater likelihood of opportunistic infections in such individuals. 
D)  Travel into and out of the United States has increased significantly. This has the potential to bring in many new pathogens that can cause new infections, even in otherwise healthy and immunocompetent individuals. 
A)  HIV individuals (with impaired immune systems) survive longer due to more effective therapies-but this allows them a longer period of time to be infected by opportunists. 
B)  Individuals in the US are living longer than ever before-but they're living with a number of chronic health issues that can impair the immune system. This leads to a greater likelihood of opportunistic infections. 
C)  Cancer treatments have improved significantly in the last 30 years-but they often suppress the immune system. This leads to a greater likelihood of opportunistic infections in such individuals. 
D)  Travel into and out of the United States has increased significantly. This has the potential to bring in many new pathogens that can cause new infections, even in otherwise healthy and immunocompetent individuals.

Question 10

The damage caused by parasites may be due to

Accepted Answer

A)  competition for nutrients. 
B)  the physical blocking of organs. 
C)  the direct digestion of host tissue. 
D)  the host's immune response. 
E)  All of the choices are correct. 
A)  competition for nutrients. 
B)  the physical blocking of organs. 
C)  the direct digestion of host tissue. 
D)  the host's immune response. 
E)  All of the choices are correct.

Question 11

Disease(s) in which the causative agent becomes latent is/are

Accepted Answer

A)  cold sores. 
B)  genital herpes. 
C)  typhus. 
D)  shingles. 
E)  All of the choices are correct. 
A)  cold sores. 
B)  genital herpes. 
C)  typhus. 
D)  shingles. 
E)  All of the choices are correct.

Question 12

Attributes of an organism that promote pathogenicity are called

Accepted Answer

A)  disease factors. 
B)  colonization factors. 
C)  mutualistic. 
D)  virulence factors. 
A)  disease factors. 
B)  colonization factors. 
C)  mutualistic. 
D)  virulence factors.

Question 13

Which of the following is true about the role normal flora plays in maintaining host health?

Accepted Answer

A)  They provide a surface that is incompatible for attachment of an invader. 
B)  They establish competition for nutrients and vitamins. 
C)  They produce antimicrobial substances. 
D)  They stimulate the immune system. 
E)  All of the choices are true. 
A)  They provide a surface that is incompatible for attachment of an invader. 
B)  They establish competition for nutrients and vitamins. 
C)  They produce antimicrobial substances. 
D)  They stimulate the immune system. 
E)  All of the choices are true.

Question 14

The series of steps used to connect an organism to a disease are known as

Accepted Answer

A)  Pasteur's postulates. 
B)  Lister's aseptics. 
C)  Linnaeus taxonomics. 
D)  Koch's postulates. 
A)  Pasteur's postulates. 
B)  Lister's aseptics. 
C)  Linnaeus taxonomics. 
D)  Koch's postulates.

Question 15

In two of Koch's postulates (#2 and #3), a pure culture of the organism is required. Which of the following would NOT be a possible consequence of using a contaminated culture?

Accepted Answer

A)  You can't necessarily attribute the illness directly to the microbe in question-it may in fact be caused by the contaminating microbe. 
B)  There's the possibility that the test animal might be acutely susceptible to the contaminating microbe, but completely resistant to the microbe you suspect causes the illness of interest. As such, when you introduce it into the test animal, it could confuse your final results. 
C)  The problem is that one microbe may be toxic to the other. It may have killed all of your suspect microbe in the culture. Therefore, you can't be sure that you're infecting your test animals with the microbe you suspect is causing the illness, or if it's only the 2nd (contaminating) microbe. 
D)  Even though there's a contaminating microbe present, so long as the original suspect microbe is also present, the disease should still manifest in test animals. It should also still be recoverable from test animals following infection. As such, there's really no consequence to using a contaminated culture. 
A)  You can't necessarily attribute the illness directly to the microbe in question-it may in fact be caused by the contaminating microbe. 
B)  There's the possibility that the test animal might be acutely susceptible to the contaminating microbe, but completely resistant to the microbe you suspect causes the illness of interest. As such, when you introduce it into the test animal, it could confuse your final results. 
C)  The problem is that one microbe may be toxic to the other. It may have killed all of your suspect microbe in the culture. Therefore, you can't be sure that you're infecting your test animals with the microbe you suspect is causing the illness, or if it's only the 2nd (contaminating) microbe. 
D)  Even though there's a contaminating microbe present, so long as the original suspect microbe is also present, the disease should still manifest in test animals. It should also still be recoverable from test animals following infection. As such, there's really no consequence to using a contaminated culture.

Question 16

Which of the following would be considered a sign of a disease?

Accepted Answer

A)  headache 
B)  pain 
C)  nausea 
D)  fever of 39°C 
A)  headache 
B)  pain 
C)  nausea 
D)  fever of 39°C

Question 17

The infectious dose of most pathogens is about equal.

Accepted Answer

A) True 
 B)False

Question 18

An example of genetic variation used in pathogen survival may be

Accepted Answer

A)  production of a comet's tail. 
B)  protease production. 
C)  inhibition of MHC Class I antigen production. 
D)  changing the pilus type. 
E)  production of a comet's tail AND protease production. 
A)  production of a comet's tail. 
B)  protease production. 
C)  inhibition of MHC Class I antigen production. 
D)  changing the pilus type. 
E)  production of a comet's tail AND protease production.

Question 19

Which is true about superantigens?

Accepted Answer

A)  They are a type of exotoxin. 
B)  They bind to MHC class II antigen on T cells. 
C)  They enhance specific antibody production. 
D)  They are processed intracellularly. 
E)  They are a type of exotoxin AND they bind to MHC class II antigen on T cells. 
A)  They are a type of exotoxin. 
B)  They bind to MHC class II antigen on T cells. 
C)  They enhance specific antibody production. 
D)  They are processed intracellularly. 
E)  They are a type of exotoxin AND they bind to MHC class II antigen on T cells.

Question 20

Organisms that are found together and interact on a more or less permanent basis are in a relationship termed

Accepted Answer

A)  mutualism. 
B)  parasitism. 
C)  symbiosis. 
D)  transient flora. 
A)  mutualism. 
B)  parasitism. 
C)  symbiosis. 
D)  transient flora.

Exam 16: Host-Microbe Interactions

The "hygiene hypothesis" proposes that

The microorganisms that are regularly found in or on the body, yet do no apparent harm are called

Why is it a good strategy for a microbe to adhere to a receptor that plays a critical function for a host cell?

Bacteria may survive phagocytosis by

A relationship in which one partner benefits and the other is unaffected is termed

Avirulent organisms are

Infection always leads to disease.

The most successful parasites are the ones that live in harmony with their hosts.

Which of the following is NOT a likely reason why diseases caused by opportunists are becoming more frequent in the US population?

The damage caused by parasites may be due to

Disease(s) in which the causative agent becomes latent is/are

Attributes of an organism that promote pathogenicity are called

Which of the following is true about the role normal flora plays in maintaining host health?

The series of steps used to connect an organism to a disease are known as

In two of Koch's postulates (#2 and #3), a pure culture of the organism is required. Which of the following would NOT be a possible consequence of using a contaminated culture?

Which of the following would be considered a sign of a disease?

The infectious dose of most pathogens is about equal.

An example of genetic variation used in pathogen survival may be

Which is true about superantigens?

Organisms that are found together and interact on a more or less permanent basis are in a relationship termed

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

Viruses, Viroids and Prions

The Innate Immune Response

The Adaptive Immune Response

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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