Question 1

A disease-causing microorganism or virus is referred to as a(n)

Accepted Answer

A)  avirulent infection. 
B)  colony. 
C)  commensal. 
D)  pathogen. 
E)  virulent. 
A)  avirulent infection. 
B)  colony. 
C)  commensal. 
D)  pathogen. 
E)  virulent.

Question 2

During incubation and convalescence a person may still spread infectious organisms.

Accepted Answer

A) True 
 B)False

Question 3

You explain to Jay that some pathogens induce non-phagocytic cells to engulf them. Gram-negative bacteria such as Salmonella often inject effector proteins that induce engulfment by host cells. In the case of Salmonella, specific proteins are delivered to intestinal epithelial cells via

Accepted Answer

A)  a type I secretion system. 
B)  a type II secretion system. 
C)  a type III secretion system. 
D)  a type IV secretion system. 
E)  a type I OR a type III secretion system. 
A)  a type I secretion system. 
B)  a type II secretion system. 
C)  a type III secretion system. 
D)  a type IV secretion system. 
E)  a type I OR a type III secretion system.

Question 4

An infectious disease is an infection that impairs the normal state of health.

Accepted Answer

A) True 
 B)False

Question 5

Please select the CORRECT definition regarding interactions between hosts and microbes.

Accepted Answer

A)  Immunocompetent-having a weakness or defect in the innate or adaptive defenses. 
B)  Parasitism-relationship between two organisms in which one partner benefits and the other is unaffected. 
C)  Dysbiosis-an imbalance in the microbiome that may be caused by taking antimicrobial medications. 
D)  Secondary infection-infection in a previously healthy person, such as measles in a child who has not had measles before. 
E)  Fc receptors-molecule that binds the antigen-binding region of an antibody. 
A)  Immunocompetent-having a weakness or defect in the innate or adaptive defenses. 
B)  Parasitism-relationship between two organisms in which one partner benefits and the other is unaffected. 
C)  Dysbiosis-an imbalance in the microbiome that may be caused by taking antimicrobial medications. 
D)  Secondary infection-infection in a previously healthy person, such as measles in a child who has not had measles before. 
E)  Fc receptors-molecule that binds the antigen-binding region of an antibody.

Question 6

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

Accepted Answer

A)  commensalism. 
B)  parasitism. 
C)  independence. 
D)  mutualism. 
E)  normal microbiota. 
A)  commensalism. 
B)  parasitism. 
C)  independence. 
D)  mutualism. 
E)  normal microbiota.

Question 7

The chemical nature of endotoxins is that of a

Accepted Answer

A)  protein. 
B)  lipopolysaccharide. 
C)  nucleic acid. 
D)  lipid. 
E)  carbohydrate. 
A)  protein. 
B)  lipopolysaccharide. 
C)  nucleic acid. 
D)  lipid. 
E)  carbohydrate.

Question 8

Would an antibody response against the B subunit of an A-B toxin protect against the effects of the toxin?

Accepted Answer

A)  Yes. If antibodies bind to the B portion, the toxin can no longer bind to target cells and will thus not affect those cells. 
B)  No. Even if antibodies bind to the B portion of the toxin, it is the A portion that actually causes damage to the cell. 
C)  Yes. If antibodies bind to the B portion, that portion of the toxin does not become activated, and thus does not damage the host cell. 
D)  No. Even if antibodies bind to the B portion of the toxin, the toxin is still taken into the host cell by phagocytosis, damaging that cell. 
E)  This question cannot be answered. The immune system does not mount a strong response against proteins, so this situation is unlikely to occur. 
A)  Yes. If antibodies bind to the B portion, the toxin can no longer bind to target cells and will thus not affect those cells. 
B)  No. Even if antibodies bind to the B portion of the toxin, it is the A portion that actually causes damage to the cell. 
C)  Yes. If antibodies bind to the B portion, that portion of the toxin does not become activated, and thus does not damage the host cell. 
D)  No. Even if antibodies bind to the B portion of the toxin, the toxin is still taken into the host cell by phagocytosis, damaging that cell. 
E)  This question cannot be answered. The immune system does not mount a strong response against proteins, so this situation is unlikely to occur.

Question 9

Why is it not possible to use Koch's postulates to show that Treponema pallidum causes syphilis?

Accepted Answer

A)  T. pallidum is a Gram-negative organism. 
B)  T. pallidum cannot be grown in pure culture. 
C)  T. pallidum causes different diseases in different hosts. 
D)  Syphilis is a polymicrobial disease; T. pallidum is only one of the causative agents involved in the disease. 
E)  T. pallidum does not contain a genome. 
A)  T. pallidum is a Gram-negative organism. 
B)  T. pallidum cannot be grown in pure culture. 
C)  T. pallidum causes different diseases in different hosts. 
D)  Syphilis is a polymicrobial disease; T. pallidum is only one of the causative agents involved in the disease. 
E)  T. pallidum does not contain a genome.

Question 10

Virulent pathogens are

Accepted Answer

A)  more likely to cause disease. 
B)  more likely to cause severe disease. 
C)  unable to cause disease. 
D)  more likely to be opportunists. 
E)  most likely normal microbiota. 
A)  more likely to cause disease. 
B)  more likely to cause severe disease. 
C)  unable to cause disease. 
D)  more likely to be opportunists. 
E)  most likely normal microbiota.

Question 11

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

Accepted Answer

A) True 
 B)False

Question 12

Which of the following would NOT be considered virulence factor(s)?

Accepted Answer

A)  Adhesins 
B)  Capsules 
C)  Endotoxins 
D)  Proteases 
E)  Ribosomes 
A)  Adhesins 
B)  Capsules 
C)  Endotoxins 
D)  Proteases 
E)  Ribosomes

Question 13

Which of the following members of the normal microbiota inhibit the growth of Candida albicans?

Accepted Answer

A)  E. coli 
B)  Lactobacillus species 
C)  Staphylococci species 
D)  Propionibacterium species 
E)  Neisseria species 
A)  E. coli 
B)  Lactobacillus species 
C)  Staphylococci species 
D)  Propionibacterium species 
E)  Neisseria species

Question 14

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

Accepted Answer

A)  People with impaired immune systems such as those with HIV disease survive longer due to more effective therapies, but this gives them a longer period of time to be infected by opportunists. 
B)  People in the U.S. 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 people receiving these treatments. 
D)  Travel into and out of the U.S. has increased significantly. This has the potential to bring in many new pathogens that can cause infections, even in otherwise healthy and immunocompetent individuals. 
E)  People in the U.S. are living longer than ever before, but their immune systems decline with age. This leads to a greater likelihood of opportunistic infections, especially if they receive any kind of invasive procedure. 
A)  People with impaired immune systems such as those with HIV disease survive longer due to more effective therapies, but this gives them a longer period of time to be infected by opportunists. 
B)  People in the U.S. 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 people receiving these treatments. 
D)  Travel into and out of the U.S. has increased significantly. This has the potential to bring in many new pathogens that can cause infections, even in otherwise healthy and immunocompetent individuals. 
E)  People in the U.S. are living longer than ever before, but their immune systems decline with age. This leads to a greater likelihood of opportunistic infections, especially if they receive any kind of invasive procedure.

Question 15

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

Accepted Answer

A)  Severe headache 
B)  Throbbing pain 
C)  Intense nausea 
D)  Fever of 39°C 
E)  All of these are signs 
A)  Severe headache 
B)  Throbbing pain 
C)  Intense nausea 
D)  Fever of 39°C 
E)  All of these are signs

Question 16

The first step in the establishment of infection is that the organism must

Accepted Answer

A)  invade host tissues. 
B)  attach to host cells. 
C)  evade phagocytes. 
D)  produce toxins. 
E)  cause apoptosis. 
A)  invade host tissues. 
B)  attach to host cells. 
C)  evade phagocytes. 
D)  produce toxins. 
E)  cause apoptosis.

Question 17

Home-canned foods should be boiled before consumption to prevent botulism. Considering that this treatment does NOT destroy endospores, why would it be helpful in preventing the disease?

Accepted Answer

A)  Because it would destroy the vegetative cells, and only the vegetative cells cause the disease. 
B)  Because it would at least weaken the endospores, making them more susceptible to elimination by our immune system. 
C)  Because the heat would denature the botulism endotoxin and inactivate it. The endotoxin is what leads to the disease symptoms, so this would make the food safer. 
D)  Because although botulism exotoxin is harmless, it has a bad odor and boiling removes this, making the food more appealing to eat. 
E)  Because the heat would denature the botulism exotoxin and inactivate it. The exotoxin is what leads to the disease symptoms, so this would make the food safer. 
A)  Because it would destroy the vegetative cells, and only the vegetative cells cause the disease. 
B)  Because it would at least weaken the endospores, making them more susceptible to elimination by our immune system. 
C)  Because the heat would denature the botulism endotoxin and inactivate it. The endotoxin is what leads to the disease symptoms, so this would make the food safer. 
D)  Because although botulism exotoxin is harmless, it has a bad odor and boiling removes this, making the food more appealing to eat. 
E)  Because the heat would denature the botulism exotoxin and inactivate it. The exotoxin is what leads to the disease symptoms, so this would make the food safer.

Question 18

People who carry and may spread pathogenic organisms without any apparent signs or symptoms of illness are called

Accepted Answer

A)  carriers. 
B)  primary infectors. 
C)  secondary infectors. 
D)  mutualists. 
E)  opportunists. 
A)  carriers. 
B)  primary infectors. 
C)  secondary infectors. 
D)  mutualists. 
E)  opportunists.

Question 19

The connection between a particular organism and a specific disease was first made by

Accepted Answer

A)  Jenner. 
B)  Pasteur. 
C)  Koch. 
D)  van Leeuwenhoek. 
E)  Hooke. 
A)  Jenner. 
B)  Pasteur. 
C)  Koch. 
D)  van Leeuwenhoek. 
E)  Hooke.

Question 20

Opportunists or opportunistic pathogens

Accepted Answer

A)  are usually saprophyte, like fungi. 
B)  take advantage of special circumstances. 
C)  are usually mutualistic. 
D)  always cause disease. 
E)  are never normal microbiota. 
A)  are usually saprophyte, like fungi. 
B)  take advantage of special circumstances. 
C)  are usually mutualistic. 
D)  always cause disease. 
E)  are never normal microbiota.

Exam 16: Host-Microbe Interactions

A disease-causing microorganism or virus is referred to as a(n)

During incubation and convalescence a person may still spread infectious organisms.

You explain to Jay that some pathogens induce non-phagocytic cells to engulf them. Gram-negative bacteria such as Salmonella often inject effector proteins that induce engulfment by host cells. In the case of Salmonella, specific proteins are delivered to intestinal epithelial cells via

An infectious disease is an infection that impairs the normal state of health.

Please select the CORRECT definition regarding interactions between hosts and microbes.

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

The chemical nature of endotoxins is that of a

Would an antibody response against the B subunit of an A-B toxin protect against the effects of the toxin?

Why is it not possible to use Koch's postulates to show that Treponema pallidum causes syphilis?

Virulent pathogens are

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

Which of the following would NOT be considered virulence factor(s)?

Which of the following members of the normal microbiota inhibit the growth of Candida albicans?

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

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

The first step in the establishment of infection is that the organism must

Home-canned foods should be boiled before consumption to prevent botulism. Considering that this treatment does NOT destroy endospores, why would it be helpful in preventing the disease?

People who carry and may spread pathogenic organisms without any apparent signs or symptoms of illness are called

The connection between a particular organism and a specific disease was first made by

Opportunists or opportunistic pathogens

Humans and the Microbial World

The Molecules of Life

Microscopy and Cell Structure

Dynamics of Microbial Growth

Control of Microbial Growth

Microbial Metabolism: Fueling Cell Growth

The Blueprint of Life, from DNA to Protein

Bacterial Genetics

Biotechnology

Identifying and Classifying Microorganisms

The Diversity of Bacteria and Archaea

The Eukaryotic Members of the Microbial World

Viruses, Viroids, and Prions

The Innate Immune Response

The Adaptive Immune Response

Immunological Disorders

Applications of Immune Responses

Epidemiology

Antimicrobial Medications

Respiratory System Infections

Skin Infections

Wound Infections

Digestive System Infections

Blood and Lymphatic Infections

Nervous System Infections

Genitourinary Tract Infections

Microbial Ecology

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

Food Microbiology

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