ch 25

Question 1

Pathogenicity is the ability

Answer 1

of the pathogen to inflict damage on the host.

Question 2

Which of the following is not a subunit of lipopolysaccharide (LPS)?
A. O-specific polysaccharide
B. lipid A
C. corepolysaccharide
D. M protein

Answer 2

M protein

Question 3

Diptheria toxin is a
A) type of endotoxin.
B) cytolytic toxin.
C) ABtoxin.
D) superantigentoxin

Answer 3

AB toxin.

Question 4

Decalcification of the tooth enamel is caused by

Answer 4

lactic acid

Question 5

Tetanus toxin causes

Answer 5

muscles to be unable to relax

Question 6

Shiga toxin is an enterotoxin that is produced by

Answer 6

Shigella dysenteriae.

Question 7

The decrease or loss of virulence of a pathogen is referred to as

Answer 7

attenuation.

Question 8

Which of the following is not important for the adherence of bacteria to host tissues?
lipopolysaccharides
capsule
adhesins
slimelayer

Answer 8

lipopolysaccharides

Question 9

Which of the following is an important factor in the development of dental caries?
high salt diet
high sugar diet
highaciddiet
lowsaltdiet

Answer 9

high sugar diet

Question 10

The spread of pathogens through the blood and lymph systems that results in a bloodborne
systemic infection is called

Answer 10

septicemia.

Question 11

Which of the following does NOT affect pathogen growth?
A) availability of microbial nutrients
B) pH
C) temperature
D) All of these affect growth.

Answer 11

all the above

Question 12

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

Answer 12

Disease

Question 13

Epithelial cells lining the respiratory tract form a

Answer 13

mucous membrane.

Question 14

What is the difference between adherence and colonization?

Answer 14

Colonization occurs when a microbe begins to grow in host tissues whereas adherence
occurs when the microbe initially attaches.

Question 15

what is a major growth-limiting micronutrient that influences microbial
growth?

Answer 15

iron

Question 16

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

Answer 16

LD50 (lethal dose)

Question 17

The best term to describe the general process by which microorganisms cause diseases is
known as

Answer 17

pathogenesis

Question 18

Septicemia is an example of a

Answer 18

systemic infection

Question 19

The process by which white blood cells ingest and kill bacteria is called

Answer 19

Phagocytosis

Question 20

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

Answer 20

endotoxins

Question 21

________ are microbial infections acquired by hospital patients with noninfectious diseases
because they are compromised hosts.

Answer 21

Nosocomial infections

Question 22

Pathogenicity pertains to the ability of a pathogen to cause disease.

Answer 22

True

Question 23

Pathogenicity islands are clusters of genes for virulence factors that are located together on
the bacterial chromosome.

Answer 23

True

Question 24

An opportunistic pathogen causes disease ONLY in the presence of normal host resistance.

Answer 24

False

Question 25

Virulence refers to a pathogen’s ability to infect or damage a host.

Answer 25

true

Question 26

A pathogen’s virulence never changes throughout a host’s life

Answer 26

False

Question 27

Cholera begins following a bite from a mosquito.

Answer 27

False

Question 28

Virulence genes may be located on mobile genetic elements

Answer 28

True

Question 29

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

Answer 29

True

Question 30

The toxic lipopolysaccharides produced by most Gram-negative bacteria are called exotoxins.

Answer 30

False

Question 31

Gram-positive bacteria produce endotoxins

Answer 31

false

Question 32

Because malnutrition can make the immune system weaker, the number of Vibrio cholera cells
necessary to produce cholera in an exposed individual is drastically reduced in individuals with
substantial malnutrition.

Answer 32

treu

Question 33

Diphtheria toxin inactivates elongation factor 2 by catalyzing the attachment of adenosine
diphosphate ribose from NAD+.

Answer 33

true

Question 34

Clostridium botulinum cannot produce toxins in improperly preserved foods.

Answer 34

false