Question 1

The exotoxin of Streptococcus pyogenes that causes destruction of phagocytic white cells is called

Accepted Answer

A) neurotoxin. 
B) enterotoxin. 
C) haemolysin. 
D) leukocidin. 
E) coagulase. 
A) neurotoxin. 
B) enterotoxin. 
C) haemolysin. 
D) leukocidin. 
E) coagulase. D

Question 2

The toxin of Clostridium tetani

Accepted Answer

A) kills cells by stopping protein synthesis. 
B) interferes with transmission in inhibitory neurons. 
C) causes a large outflow of water and ions from intestinal epithelial cells. 
D) blocks the release of acetylcholine at neuromuscular junctions. 
E) kills cells by damaging the cell membrane. 
A) kills cells by stopping protein synthesis. 
B) interferes with transmission in inhibitory neurons. 
C) causes a large outflow of water and ions from intestinal epithelial cells. 
D) blocks the release of acetylcholine at neuromuscular junctions. 
E) kills cells by damaging the cell membrane. B

Question 3

Bacterial exotoxins are characteristically

Accepted Answer

A) lethal only in very large amounts. 
B) proteins. 
C) non-specific in their mode of action. 
D) produced only by bacteria which deeply invade tissues. 
E) all of the above. 
A) lethal only in very large amounts. 
B) proteins. 
C) non-specific in their mode of action. 
D) produced only by bacteria which deeply invade tissues. 
E) all of the above. B

Question 4

Which of the following DO NOT induce an inflammatory or immune response when infecting a person?

Accepted Answer

A) Viruses. 
B) Protozoa. 
C) Bacteria. 
D) Prions. 
E) All of the above. 
A) Viruses. 
B) Protozoa. 
C) Bacteria. 
D) Prions. 
E) All of the above.

Question 5

The α-toxin of Staphylococcus aureus that breaks down red blood cells is a

Accepted Answer

A) neurotoxin. 
B) lymphotoxin. 
C) haemolysin. 
D) leukocidin. 
E) coagulase. 
A) neurotoxin. 
B) lymphotoxin. 
C) haemolysin. 
D) leukocidin. 
E) coagulase.

Question 6

Which of the following enzymes produced by some bacteria is used therapeutically to dissolve fibrin clots?

Accepted Answer

A) Coagulase. 
B) Streptokinase. 
C) Hyaluronidase. 
D) Collagenase. 
E) Keratinase. 
A) Coagulase. 
B) Streptokinase. 
C) Hyaluronidase. 
D) Collagenase. 
E) Keratinase.

Question 7

Which of the following structures enables microbes to attach to cell surfaces?

Accepted Answer

A) Adhesins. 
B) Pili. 
C) Fimbriae. 
D) Glycocalyx. 
E) All of the above. 
A) Adhesins. 
B) Pili. 
C) Fimbriae. 
D) Glycocalyx. 
E) All of the above.

Question 8

Which of the following viruses can cause tumour formation?

Accepted Answer

A) Cutaneous wart viruses. 
B) Genital wart viruses. 
C) Hepatitis B virus. 
D) Hepatitis C virus. 
E) All of the above. 
A) Cutaneous wart viruses. 
B) Genital wart viruses. 
C) Hepatitis B virus. 
D) Hepatitis C virus. 
E) All of the above.

Question 9

A toxoid is

Accepted Answer

A) a type of antibody that combines with a toxin. 
B) an enzyme that destroys toxins. 
C) a substance produced by some bacteria. 
D) an inactivated toxin used in vaccines. 
E) the active substance in some drug preparations. 
A) a type of antibody that combines with a toxin. 
B) an enzyme that destroys toxins. 
C) a substance produced by some bacteria. 
D) an inactivated toxin used in vaccines. 
E) the active substance in some drug preparations.

Question 10

A biofilm

Accepted Answer

A) enables bacteria to move through fluids. 
B) facilitates quorum sensing between bacterial cells. 
C) allows host defence cells to gain access to bacteria. 
D) is not normally produced in the human body. 
E) is readily removed with disinfectants. 
A) enables bacteria to move through fluids. 
B) facilitates quorum sensing between bacterial cells. 
C) allows host defence cells to gain access to bacteria. 
D) is not normally produced in the human body. 
E) is readily removed with disinfectants.

Question 11

Septic shock is caused by

Accepted Answer

A) the presence of large amounts of endotoxin in the body. 
B) the combined action of several neurotoxins. 
C) disseminated intravascular coagulation. 
D) insufficient toxoids present in the body. 
E) the blockage of small blood vessels by colonies of bacteria. 
A) the presence of large amounts of endotoxin in the body. 
B) the combined action of several neurotoxins. 
C) disseminated intravascular coagulation. 
D) insufficient toxoids present in the body. 
E) the blockage of small blood vessels by colonies of bacteria.

Question 12

Streptokinase

Accepted Answer

A) is an enzyme that breaks down fibrin. 
B) is an endotoxin of Streptococcus. 
C) coagulates fibrinogen. 
D) destroys human white cells. 
E) none of the above. 
A) is an enzyme that breaks down fibrin. 
B) is an endotoxin of Streptococcus. 
C) coagulates fibrinogen. 
D) destroys human white cells. 
E) none of the above.

Question 13

Microorganisms can avoid body defences by

Accepted Answer

A) hiding in privileged sites. 
B) repeatedly changing their surface antigens. 
C) destroying some host defences. 
D) remaining hidden inside host cells. 
E) all of the above. 
A) hiding in privileged sites. 
B) repeatedly changing their surface antigens. 
C) destroying some host defences. 
D) remaining hidden inside host cells. 
E) all of the above.

Question 14

The ability of the tapeworm Echinococcus granulosis to form and reside within fluid-filled cysts inside the human body is an example of

Accepted Answer

A) antigenic shift. 
B) antigenic drift. 
C) concealment. 
D) immunosuppression. 
E) cellular transformation. 
A) antigenic shift. 
B) antigenic drift. 
C) concealment. 
D) immunosuppression. 
E) cellular transformation.

Question 15

Which of the following does NOT help bacteria to spread through body tissues?

Accepted Answer

A) Hyaluronidase. 
B) Collagenase. 
C) Keratinase. 
D) Kinase. 
E) Coagulase. 
A) Hyaluronidase. 
B) Collagenase. 
C) Keratinase. 
D) Kinase. 
E) Coagulase.

Question 16

A bacterial capsule can increase an organism's virulence because it

Accepted Answer

A) breaks into fragments called endotoxins. 
B) is toxic for phagocytes. 
C) produces severe cytopathic effects. 
D) helps the organism to evade phagocytosis. 
E) specifically affects nerve cells. 
A) breaks into fragments called endotoxins. 
B) is toxic for phagocytes. 
C) produces severe cytopathic effects. 
D) helps the organism to evade phagocytosis. 
E) specifically affects nerve cells.

Question 17

Viruses can attach to target cells by

Accepted Answer

A) hooks. 
B) fibronectin. 
C) pili. 
D) suckers. 
E) envelope spikes. 
A) hooks. 
B) fibronectin. 
C) pili. 
D) suckers. 
E) envelope spikes.

Question 18

The symptoms characteristic of tetanus are due to

Accepted Answer

A) the production of gas in the wound. 
B) destruction of nerve cells. 
C) spread of the organism through the body. 
D) an exotoxin. 
E) all of the above. 
A) the production of gas in the wound. 
B) destruction of nerve cells. 
C) spread of the organism through the body. 
D) an exotoxin. 
E) all of the above.

Question 19

The toxin of Vibrio cholerae

Accepted Answer

A) kills cells by stopping protein synthesis. 
B) interferes with synaptic transmission in inhibitory interneurones. 
C) causes a loss of water and ions from intestinal epithelial cells. 
D) blocks the release of acetylcholine at neuromuscular junctions. 
E) kills cells by damaging the cell membrane. 
A) kills cells by stopping protein synthesis. 
B) interferes with synaptic transmission in inhibitory interneurones. 
C) causes a loss of water and ions from intestinal epithelial cells. 
D) blocks the release of acetylcholine at neuromuscular junctions. 
E) kills cells by damaging the cell membrane.

Question 20

Which of the following enzymes can be used to distinguish between different species of staphylococci?

Accepted Answer

A) Hyaluronidase. 
B) Fibrinolysin. 
C) Streptokinase. 
D) Coagulase. 
E) Haemolysin. 
A) Hyaluronidase. 
B) Fibrinolysin. 
C) Streptokinase. 
D) Coagulase. 
E) Haemolysin.

Exam 10: Pathogenic Mechanisms and Evasion Strategies of Microorganisms

The exotoxin of Streptococcus pyogenes that causes destruction of phagocytic white cells is called

The toxin of Clostridium tetani

Bacterial exotoxins are characteristically

Which of the following DO NOT induce an inflammatory or immune response when infecting a person?

The α-toxin of Staphylococcus aureus that breaks down red blood cells is a

Which of the following enzymes produced by some bacteria is used therapeutically to dissolve fibrin clots?

Which of the following structures enables microbes to attach to cell surfaces?

Which of the following viruses can cause tumour formation?

A toxoid is

A biofilm

Septic shock is caused by

Streptokinase

Microorganisms can avoid body defences by

The ability of the tapeworm Echinococcus granulosis to form and reside within fluid-filled cysts inside the human body is an example of

Which of the following does NOT help bacteria to spread through body tissues?

A bacterial capsule can increase an organism's virulence because it

Viruses can attach to target cells by

The symptoms characteristic of tetanus are due to

The toxin of Vibrio cholerae

Which of the following enzymes can be used to distinguish between different species of staphylococci?

The Invisible World

Biological Reactions in Microbial Cells

Bacteria

Genes and Biotechnology

Viruses and Viral Diseases

Eucaryotic Microorganisms: Fungi, protozoa and Multicellular Organisms

Hostmicrobe Interactions and Principles of Disease

Epidemiology: How Diseases Are Spread

The Bodys Defence Systems

Principles of Sterilisation and Disinfection

Antimicrobial Therapy

Infection Control in Healthcare Facilities

Issues in Public Health

Microbial Techniques for Diagnosis of Infection

Skin, wound and Eye Infections

Respiratory Tract Infections

Gastrointestinal Tract Infections

Cardiovascular and Multisystem Infections

Infections of the Nervous System

Infections of the Urinary and Reproductive Systems

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