Question 1

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 2

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 3

The normal microbiota provides protection against potentially harmful organisms and stimulates the immune system. Why would the immune responses to members of the normal microbiota cross-react with pathogens?

Accepted Answer

A)  Because one person's normal microbiota is another person's pathogen-when we pick up "normal" microbes from a different person, they will always cause infection within us. 
B)  Because pathogens are often more virulent strains of our own normal microbiota, so they will appear similar to those cells to our immune system, and may be acted upon by our immune responses. 
C)  Because the normal microbiota keeps the adaptive immune responses tuned up, active, and ready to respond to broad, general categories of microbes such as Gram-positive and Gram-negative bacteria and viruses. 
D)  Because if the immune system isn't used on a regular basis, it loses the ability to respond to pathogens. The normal microbiota keeps the system going so that it can be ready to respond to pathogens when we're exposed to them. 
E)  Because normal microbiota are often more virulent strains of our pathogens, so they will appear similar to those cells to our immune system, and may be acted upon by our immune responses. 
A)  Because one person's normal microbiota is another person's pathogen-when we pick up "normal" microbes from a different person, they will always cause infection within us. 
B)  Because pathogens are often more virulent strains of our own normal microbiota, so they will appear similar to those cells to our immune system, and may be acted upon by our immune responses. 
C)  Because the normal microbiota keeps the adaptive immune responses tuned up, active, and ready to respond to broad, general categories of microbes such as Gram-positive and Gram-negative bacteria and viruses. 
D)  Because if the immune system isn't used on a regular basis, it loses the ability to respond to pathogens. The normal microbiota keeps the system going so that it can be ready to respond to pathogens when we're exposed to them. 
E)  Because normal microbiota are often more virulent strains of our pathogens, so they will appear similar to those cells to our immune system, and may be acted upon by our immune responses.

Question 4

Which of the following is/are true about endotoxins?

Accepted Answer

A)  Lipid A is the toxic portion of the molecule. 
B)  The toxic effects depend on the bacteria from which it came. 
C)  The lipid A portion is heat sensitive. 
D)  They are proteins. 
E)  The toxic effects depend on the bacteria from which it came AND they are proteins. 
A)  Lipid A is the toxic portion of the molecule. 
B)  The toxic effects depend on the bacteria from which it came. 
C)  The lipid A portion is heat sensitive. 
D)  They are proteins. 
E)  The toxic effects depend on the bacteria from which it came AND they are proteins.

Question 5

You explain to the parents that pertussis is a highly contagious disease, meaning that

Accepted Answer

A)  it is a disease that can be easily transmitted from one host to another. 
B)  it is a disease that is not easily transmitted from one host to another. 
C)  it is a disease that is acquired by inhaling the pathogen. 
D)  it is a disease that is acquired via the placenta. 
E)  it is a disease caused by an opportunistic pathogen. 
A)  it is a disease that can be easily transmitted from one host to another. 
B)  it is a disease that is not easily transmitted from one host to another. 
C)  it is a disease that is acquired by inhaling the pathogen. 
D)  it is a disease that is acquired via the placenta. 
E)  it is a disease caused by an opportunistic pathogen.

Question 6

If a disease affects only a human and not an animal, then it would be difficult to fulfill Koch's postulate number ________.

Accepted Answer

A)  4 
B)  3 
C)  2 
D)  1 
E)  8 
A)  4 
B)  3 
C)  2 
D)  1 
E)  8

Question 7

Which of the following factors is not considered important for the establishment of an infection?

Accepted Answer

A)  Adherence 
B)  Dose 
C)  Toxicity 
D)  Virulence factors 
E)  None of these is important 
A)  Adherence 
B)  Dose 
C)  Toxicity 
D)  Virulence factors 
E)  None of these is important

Question 8

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 9

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

Accepted Answer

A)  abnormal microbiota. 
B)  normal microbiota. 
C)  transient microbiota. 
D)  variant microbiota. 
E)  random biota. 
A)  abnormal microbiota. 
B)  normal microbiota. 
C)  transient microbiota. 
D)  variant microbiota. 
E)  random biota.

Question 10

You explain to Jay that infections and the associated diseases are often described according to the timing and duration of the symptoms. You define the different categories to him, telling him that he has

Accepted Answer

A)  a chronic infection, which is an infection that develops slowly and may last for months or years. 
B)  a latent infection-the microbe causing Jay's illness will continue to exist in him, although likely without causing any symptoms. 
C)  a localized infection, in which the microbe is limited to a small area-in Jay's case the gastrointestinal tract. 
D)  an inopportunistic infection, because Salmonella species are part of a person's gastrointestinal normal microbiota. 
E)  an acute infection, characterized by symptoms that develop quickly but last only a short time. 
A)  a chronic infection, which is an infection that develops slowly and may last for months or years. 
B)  a latent infection-the microbe causing Jay's illness will continue to exist in him, although likely without causing any symptoms. 
C)  a localized infection, in which the microbe is limited to a small area-in Jay's case the gastrointestinal tract. 
D)  an inopportunistic infection, because Salmonella species are part of a person's gastrointestinal normal microbiota. 
E)  an acute infection, characterized by symptoms that develop quickly but last only a short time.

Question 11

Infection always leads to disease.

Accepted Answer

A) True 
 B)False

Question 12

Bacteria that resist killing by complement proteins are termed

Accepted Answer

A)  serum strong. 
B)  serum resistant. 
C)  balanced pathogens. 
D)  mutualistic. 
E)  mutualistic AND serum resistant. 
A)  serum strong. 
B)  serum resistant. 
C)  balanced pathogens. 
D)  mutualistic. 
E)  mutualistic AND serum resistant.

Question 13

Please select the FALSE statement regarding viral avoidance of the immune response.

Accepted Answer

A)  Some viruses interfere with antigen presentation by MHC class I molecules. 
B)  Some viruses produce enzymes that, when activated, make holes in the phagocyte membrane, killing the cell. 
C)  Some viruses move directly from one cell to its immediate neighbors, thus avoiding antibodies. 
D)  Some viruses encode proteins that shut down expression of host genes such as those encoding IFNs and AVPs. 
E)  Some viruses display "fake" MHC class I molecules, tricking the immune system into believing that the cell is uninfected. 
A)  Some viruses interfere with antigen presentation by MHC class I molecules. 
B)  Some viruses produce enzymes that, when activated, make holes in the phagocyte membrane, killing the cell. 
C)  Some viruses move directly from one cell to its immediate neighbors, thus avoiding antibodies. 
D)  Some viruses encode proteins that shut down expression of host genes such as those encoding IFNs and AVPs. 
E)  Some viruses display "fake" MHC class I molecules, tricking the immune system into believing that the cell is uninfected.

Question 14

The chemical nature of exotoxins is that of a

Accepted Answer

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

Question 15

The infectious dose

Accepted Answer

A)  is the same for all microorganisms. 
B)  may be 10-100 cells for Salmonella. 
C)  is defined as the number of microbes needed to cause infection. 
D)  is defined as the number of microbes needed to kill the host. 
E)  is the same for all bacteria but varies for viruses. 
A)  is the same for all microorganisms. 
B)  may be 10-100 cells for Salmonella. 
C)  is defined as the number of microbes needed to cause infection. 
D)  is defined as the number of microbes needed to kill the host. 
E)  is the same for all bacteria but varies for viruses.

Question 16

Obligate intracellular parasites may be grown in special synthetic media.

Accepted Answer

A) True 
 B)False

Question 17

The parents tell you that their baby has already had a DTaP vaccine and that they thought this would protect the child from pertussis. You explain that this vaccine is given in a series and that with each shot in the series, the child's immunity will increase. You explain that while their baby was born with ________ immunity, she only started to develop ________ immunity after birth, so is still vulnerable to certain infections such as pertussis.

Accepted Answer

A)  adaptive; innate 
B)  innate; adaptive 
C)  cell-mediated; humoral 
D)  humoral; cell-mediated 
E)  cell-mediated; B-cell 
A)  adaptive; innate 
B)  innate; adaptive 
C)  cell-mediated; humoral 
D)  humoral; cell-mediated 
E)  cell-mediated; B-cell

Question 18

The process by which infectious agents are ingested by host cells is

Accepted Answer

A)  exocytosis. 
B)  pinocytosis. 
C)  endocytosis. 
D)  phagosome fusion. 
E)  endofusion. 
A)  exocytosis. 
B)  pinocytosis. 
C)  endocytosis. 
D)  phagosome fusion. 
E)  endofusion.

Question 19

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 20

Newborn babies acquire microbiota

Accepted Answer

A)  when passing through the birth canal. 
B)  through breastfeeding. 
C)  by contact with the mother's skin. 
D)  from the environment. 
E)  All of the above are a source of microbiota. 
A)  when passing through the birth canal. 
B)  through breastfeeding. 
C)  by contact with the mother's skin. 
D)  from the environment. 
E)  All of the above are a source of microbiota.

Exam 16: Host-Microbe Interactions

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

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

The normal microbiota provides protection against potentially harmful organisms and stimulates the immune system. Why would the immune responses to members of the normal microbiota cross-react with pathogens?

Which of the following is/are true about endotoxins?

You explain to the parents that pertussis is a highly contagious disease, meaning that

If a disease affects only a human and not an animal, then it would be difficult to fulfill Koch's postulate number ________.

Which of the following factors is not considered important for the establishment of an infection?

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?

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

You explain to Jay that infections and the associated diseases are often described according to the timing and duration of the symptoms. You define the different categories to him, telling him that he has

Infection always leads to disease.

Bacteria that resist killing by complement proteins are termed

Please select the FALSE statement regarding viral avoidance of the immune response.

The chemical nature of exotoxins is that of a

The infectious dose

Obligate intracellular parasites may be grown in special synthetic media.

The process by which infectious agents are ingested by host cells is

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

Newborn babies acquire microbiota

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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