BIOL 250 Final Exam Study Guide and Homework UPDATED
ACTUAL Questions and CORRECT Answers
The lipopolysaccharide found in the outer membrane of a
Gram-negative bacterial cells is of medical importance
because it acts as a(n):
a. endotoxin
b. antibiotic
c. toxoid
d. adhesin
The degree of pathogenicity of an organism is known as c
the
a) antigenicity.
b) toxigenicity.
c) virulence.
d) cytopathic effect.
The antibiotics commonly used to treat bacterial d
infections
a) always act by inhibiting the cross linking of
polysaccharides in bacterial cell walls
b) always act by inhibiting bacterial protein synthesis
c) inhibit various biochemical processes that occur in
both prokaryotes and eukaryotes
d) none of the above
Exotoxins are: b
a) lipopolysaccharides (LPS) found on the surface of
some bacteria.
b) proteins made by pathogenic bacteria that are
virulence determinants.
c) molecules that are embedded in the S layer of Gram-
positive pathogenic bacteria that cause fever during
infectious disease.
d) none of these statements are correct.
The "targets" for antibiotics used to treat bacterial c
infections are:
a) found only in pathogenic microorganisms.
b) are only various steps in protein biosynthesis.
c) biochemical processes that are only found in bacteria
and not eukaryotic hosts.
d) statements (a) and (c) are both correct.
, Beta-lactam antibiotics: e
a) inhibit protein synthesis.
b) include penicillins and cephalosporins.
c) inhibit the transpeptidase that crosslinks N-
acetylglucosamine and N-acetylmuramic acid, which are
polysaccharides found in bacterial cell walls.
d) statements (a) and (b) are both correct.
e) statements (b) and (c) are both correct.
If an antibiotic prevents bacteria from growing, then its c
action is termed
a) bactericidal.
b) selectively toxic.
c) bacteriostatic.
d) toxic.
To cause an infectious disease in humans a pathogen a
must first:
a) breach the host's physical and chemical barriers.
b) survive the host's innate defense mechanisms.
c) surmount the host's adaptive immunity.
d) all of the statements above are correct.
e) none of the statements above are correct.
Which of the following is NOT important for the a
adherence of bacteria to host tissues?
a) lipopolysaccharides
b) capsule
c) adhesins
d) slime layer
________ are toxic proteins released from the pathogen b
during normal growth.
a) Endotoxins
b) Exotoxins
c) Macrotoxins
d) Microtoxins
The dose of an antigen that kills 50% of animals in a test c
group and is used to estimate the virulence of a
pathogen is known as
a) Antigen dose50.
b) Virulence-50.
c) LD50 (lethal dose50).
d) Death rate-50
True or False: Pathogenicity islands are clusters of genes True
for virulence factors that are located together on the
bacterial chromosome.
ACTUAL Questions and CORRECT Answers
The lipopolysaccharide found in the outer membrane of a
Gram-negative bacterial cells is of medical importance
because it acts as a(n):
a. endotoxin
b. antibiotic
c. toxoid
d. adhesin
The degree of pathogenicity of an organism is known as c
the
a) antigenicity.
b) toxigenicity.
c) virulence.
d) cytopathic effect.
The antibiotics commonly used to treat bacterial d
infections
a) always act by inhibiting the cross linking of
polysaccharides in bacterial cell walls
b) always act by inhibiting bacterial protein synthesis
c) inhibit various biochemical processes that occur in
both prokaryotes and eukaryotes
d) none of the above
Exotoxins are: b
a) lipopolysaccharides (LPS) found on the surface of
some bacteria.
b) proteins made by pathogenic bacteria that are
virulence determinants.
c) molecules that are embedded in the S layer of Gram-
positive pathogenic bacteria that cause fever during
infectious disease.
d) none of these statements are correct.
The "targets" for antibiotics used to treat bacterial c
infections are:
a) found only in pathogenic microorganisms.
b) are only various steps in protein biosynthesis.
c) biochemical processes that are only found in bacteria
and not eukaryotic hosts.
d) statements (a) and (c) are both correct.
, Beta-lactam antibiotics: e
a) inhibit protein synthesis.
b) include penicillins and cephalosporins.
c) inhibit the transpeptidase that crosslinks N-
acetylglucosamine and N-acetylmuramic acid, which are
polysaccharides found in bacterial cell walls.
d) statements (a) and (b) are both correct.
e) statements (b) and (c) are both correct.
If an antibiotic prevents bacteria from growing, then its c
action is termed
a) bactericidal.
b) selectively toxic.
c) bacteriostatic.
d) toxic.
To cause an infectious disease in humans a pathogen a
must first:
a) breach the host's physical and chemical barriers.
b) survive the host's innate defense mechanisms.
c) surmount the host's adaptive immunity.
d) all of the statements above are correct.
e) none of the statements above are correct.
Which of the following is NOT important for the a
adherence of bacteria to host tissues?
a) lipopolysaccharides
b) capsule
c) adhesins
d) slime layer
________ are toxic proteins released from the pathogen b
during normal growth.
a) Endotoxins
b) Exotoxins
c) Macrotoxins
d) Microtoxins
The dose of an antigen that kills 50% of animals in a test c
group and is used to estimate the virulence of a
pathogen is known as
a) Antigen dose50.
b) Virulence-50.
c) LD50 (lethal dose50).
d) Death rate-50
True or False: Pathogenicity islands are clusters of genes True
for virulence factors that are located together on the
bacterial chromosome.
