TEST BANK FOR TEXTBOOK OF
DIAGNOSTIC MICROBIOLOGY
QUESTIONS AND GREDED A+
ANSWERS
Chapter 01: Bacterial Cell Structure, Physiology, Metabolism, and Genetics
Mahon: Textbook of Diagnostic Microbiology, 6th Edition
The three regions of the lipopolysaccharide include all the following,
except
a. antigenic O-specific polysaccharide.
,b. mycolic acid.
c. core polysaccharide.
d. endotoxin (inner lipid A).
ANS: B
Antigenic O-specific polysaccharide, core polysaccharide, and endotoxin are
all part of the lipopolysaccharide layer.
The outer cell wall of the gram-negative bacteria serves three important
functions, which includes all the following, except:
e. It provides an attachment site for the flagella, which will act in
locomotion.
f. It acts as a barrier to hydrophobic compounds and harmful substances. c.
It acts as a sieve.
d. It provides attachment sites that enhance adhesion to host cells.
ANS: A
The outer cell wall of gram-negative bacteria acts as a barrier to hydrophobic
compounds and harmful substances, acts as a sieve, and provides attachment
sites that enhance adhesion to host cells. Flagella attach to the cell membrane,
not to the cell wall.
, Mycoplasma and Ureaplasma spp. must have media supplemented with
serum or sugar as nutrients and because
g. their cell walls contain only peptidoglycan.
h. they lack cell walls.
i. the sterols in their cell walls are soluble in normal bacterial media.
j. their cell walls contain detoxifying enzymes.
ANS: B
These two genera have no cell walls, so the other choices are not appropriate.
Serum and sugar are needed nutrients and assist with osmotic balance of the
media.
What is the purpose of a capsule?
k. Prevent osmotic rupture of the cell membrane
l. Make up the periplasmic space
m. Act as a virulence factor in helping the pathogen evade phagocytosis
n. Provide an attachment site for somatic antigens
ANS: C
The capsule acts as a virulence factor in helping the pathogen evade
phagocytosis because antibodies have difficulty attaching to the capsule of
bacteria and therefore are unable to prepare the organism for ingestion. The
DIAGNOSTIC MICROBIOLOGY
QUESTIONS AND GREDED A+
ANSWERS
Chapter 01: Bacterial Cell Structure, Physiology, Metabolism, and Genetics
Mahon: Textbook of Diagnostic Microbiology, 6th Edition
The three regions of the lipopolysaccharide include all the following,
except
a. antigenic O-specific polysaccharide.
,b. mycolic acid.
c. core polysaccharide.
d. endotoxin (inner lipid A).
ANS: B
Antigenic O-specific polysaccharide, core polysaccharide, and endotoxin are
all part of the lipopolysaccharide layer.
The outer cell wall of the gram-negative bacteria serves three important
functions, which includes all the following, except:
e. It provides an attachment site for the flagella, which will act in
locomotion.
f. It acts as a barrier to hydrophobic compounds and harmful substances. c.
It acts as a sieve.
d. It provides attachment sites that enhance adhesion to host cells.
ANS: A
The outer cell wall of gram-negative bacteria acts as a barrier to hydrophobic
compounds and harmful substances, acts as a sieve, and provides attachment
sites that enhance adhesion to host cells. Flagella attach to the cell membrane,
not to the cell wall.
, Mycoplasma and Ureaplasma spp. must have media supplemented with
serum or sugar as nutrients and because
g. their cell walls contain only peptidoglycan.
h. they lack cell walls.
i. the sterols in their cell walls are soluble in normal bacterial media.
j. their cell walls contain detoxifying enzymes.
ANS: B
These two genera have no cell walls, so the other choices are not appropriate.
Serum and sugar are needed nutrients and assist with osmotic balance of the
media.
What is the purpose of a capsule?
k. Prevent osmotic rupture of the cell membrane
l. Make up the periplasmic space
m. Act as a virulence factor in helping the pathogen evade phagocytosis
n. Provide an attachment site for somatic antigens
ANS: C
The capsule acts as a virulence factor in helping the pathogen evade
phagocytosis because antibodies have difficulty attaching to the capsule of
bacteria and therefore are unable to prepare the organism for ingestion. The
