Question 1

What are the different categories of exotoxins, and how do they function?

Accepted Answer

The three categories are AB toxins, cyto...

Question 2

Which of the following is NOT an example of an AB toxin?

Accepted Answer

A)   shiga-like toxin
B)   hemolysins
C)   botulinum toxin
D)   tetanus toxinE) B) and C)
F) None of the above

Question 3

________ in saliva cleaves glycosidic linkages in the peptidoglycan that is present in bacterial cell walls, weakening the wall and potentially causing cell lysis.

Accepted Answer

A)   Mucus
B)   Lysozyme
C)   Fibrin
D)   Lipid AE) A) and B)
F) A) and C) B

Question 4

R plasmids help prevent the spread of virulence factors.

Accepted Answer

A) True 
 B)False

Question 5

________ is a damage or injury to a host organism that impairs its function.

Accepted Answer

A)   Trauma
B)   Infection
C)   Disease
D)   TransmissionE) B) and C)
F) All of the above

Question 6

Escherichia coli is commonly found in the normal human microbiota, but some strains can cause severe illness. What is the difference between pathogenic and non-pathogenic E. coli in relation to the human host?

Accepted Answer

Most nonpathogenic E. coli strains are f...

Question 7

________ are toxic proteins released from the pathogen during normal growth.

Accepted Answer

A)   Endotoxins
B)   Exotoxins
C)   Macrotoxins
D)   MicrotoxinsE) All of the above
F) C) and D)

Question 8

Cholera begins following a bite from a mosquito.

Accepted Answer

A) True 
 B)False

Question 9

The dose of an antigen that kills 50% of animals in a test group and is used to estimate the virulence of a pathogen is known as

Accepted Answer

A)   Antigen dose₅₀.
B)   Virulence-50.
C)   LD₅₀ (lethal dose₅₀) .
D)   Death rate-50.E) B) and C)
F) C) and D)

Question 10

Which of the following is a major growth-limiting micronutrient that influences microbial growth?

Accepted Answer

A)   iron
B)   water
C)   vitamin K
D)   sugarE) B) and C)
F) B) and D)

Question 11

Virulence genes may be located on mobile genetic elements.

Accepted Answer

A) True 
 B)False  TRUE

Question 12

Explain how diet plays a role in the development of dental caries.

Accepted Answer

Sugar in the human diet contributes to d...

Question 13

Pathogen virulence NEVER changes throughout a hostʹs life.

Accepted Answer

A) True 
 B)False

Question 14

The condition that results when some bacteria are shed in the bloodstream and distributed to distant parts of the body but do not reproduce in the blood is called

Accepted Answer

A)   septicemia.
B)   bacteremia.
C)   uremia.
D)   erythemia.E) C) and D)
F) B) and C)

Question 15

An endogenous pyrogen is

Accepted Answer

A)   a chemical from the bacterial cell wall that causes fever.
B)   a chemical produced by a host's own immune system that causes fever.
C)   a chemical released by a bacterial cell that causes fever.
D)   a chemical produced within a bacterial cell that is released during cell division or at death of the bacterium, at which point it causes fever.E) A) and B)
F) None of the above

Question 16

Compared with an endotoxin, would a bacterial exotoxin generally be more likely to function after it had been significantly heated?

Accepted Answer

A)   Yes, because exotoxins are very heat stable compared to endotoxins.
B)   Yes, because exotoxins are proteins and non-living but endotoxins are part of the bacterial cell wall.
C)   No, because exotoxins are carbohydrates and endotoxins are proteins.
D)   No, because exotoxins are heat-labile and less resistant to heating than endotoxins.E) A) and B)
F) A) and C)

Question 17

Which of the following pathogens does NOT use capsules or a slime layer for attachment?

Accepted Answer

A)   Vibrio cholera
B)   Streptococcus pneumonia
C)   Bacillus anthracis
D)   All of these pathogens use capsules or slime layers for attachment.E) A) and D)
F) A) and C) A

Question 18

Pathogenicity and virulence differ in that

Accepted Answer

A)   pathogenicity refers to the overall ability of a microbe to cause disease, whereas virulence refers to the ability of one microbe to cause disease relative to another.
B)   virulence refers to the overall ability of a microbe to cause disease, whereas pathogenicity refers to the ability of one microbe to cause disease relative to another.
C)   pathogenicity only refers to pathogens, whereas virulence refers to any microbe that can cause an infection.
D)   virulence only refers to pathogens, whereas pathogenicity refers to any microbe that can cause an infection.E) B) and D)
F) B) and C)

Question 19

Tetanus toxin causes

Accepted Answer

A)   muscles to be unable to relax.
B)   muscles to be unable to contract.
C)   severe diarrhea.
D)   hemolytic uremic syndrome.E) A) and B)
F) A) and C)

Question 20

Invasion is the ability of a pathogen to enter into host cells or tissues, spread, and cause disease.

Accepted Answer

A) True 
 B)False

Exam 25: Microbial Infection and Pathogenesis

What are the different categories of exotoxins, and how do they function?

Correct AnswerverifiedThe three categories are AB toxins, cyto...View AnswerShow Answer

Which of the following is NOT an example of an AB toxin?

Correct AnswerverifiedShow Answer

________ in saliva cleaves glycosidic linkages in the peptidoglycan that is present in bacterial cell walls, weakening the wall and potentially causing cell lysis.

Correct AnswerverifiedB

R plasmids help prevent the spread of virulence factors.

Correct AnswerverifiedShow Answer

________ is a damage or injury to a host organism that impairs its function.

Correct AnswerverifiedShow Answer

Escherichia coli is commonly found in the normal human microbiota, but some strains can cause severe illness. What is the difference between pathogenic and non-pathogenic E. coli in relation to the human host?

Correct AnswerverifiedMost nonpathogenic E. coli strains are f...View AnswerShow Answer

________ are toxic proteins released from the pathogen during normal growth.

Correct AnswerverifiedShow Answer

Cholera begins following a bite from a mosquito.

Correct AnswerverifiedShow Answer

The dose of an antigen that kills 50% of animals in a test group and is used to estimate the virulence of a pathogen is known as

Correct AnswerverifiedShow Answer

Which of the following is a major growth-limiting micronutrient that influences microbial growth?

Correct AnswerverifiedShow Answer

Virulence genes may be located on mobile genetic elements.

Correct AnswerverifiedTRUE

Explain how diet plays a role in the development of dental caries.

Correct AnswerverifiedSugar in the human diet contributes to d...View AnswerShow Answer

Pathogen virulence NEVER changes throughout a hostʹs life.

Correct AnswerverifiedShow Answer

The condition that results when some bacteria are shed in the bloodstream and distributed to distant parts of the body but do not reproduce in the blood is called

Correct AnswerverifiedShow Answer

An endogenous pyrogen is

Correct AnswerverifiedShow Answer

Compared with an endotoxin, would a bacterial exotoxin generally be more likely to function after it had been significantly heated?

Correct AnswerverifiedShow Answer

Which of the following pathogens does NOT use capsules or a slime layer for attachment?

Correct AnswerverifiedA

Pathogenicity and virulence differ in that

Correct AnswerverifiedShow Answer

Tetanus toxin causes

Correct AnswerverifiedShow Answer

Invasion is the ability of a pathogen to enter into host cells or tissues, spread, and cause disease.

Correct AnswerverifiedShow Answer

Correct Answer
verified
The three categories are AB toxins, cyto...
View Answer

Correct Answer
verified

Correct Answer
verified
B

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
Most nonpathogenic E. coli strains are f...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
TRUE

Correct Answer
verified
Sugar in the human diet contributes to d...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
A

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified