BIOL 2117 ACTUAL EXAM PAPER 2026
QUESTIONS AND SOLUTIONS GRADED A+
◉ which of the following is a pathogen that could not be identified
by the original Koch's postulates
A. S. aureus
B. P. aeruginosa
C. HIV
D. S. enetrica serovar typhimurium
Answer: C. HIV
◉ Pathogen A has an ID50 of 50 particles, pathogen B has an ID50 of
1,000 particles, and pathogen C has an ID50 of 1 × 106 particles.
Which pathogen is most virulent?
A. pathogen A
B. pathogen B
C. pathogen C
Answer: a. Pathogen A
◉ You have recently identified a new toxin. It is produced by a gram-
negative bacterium. It is composed mostly of protein, has high
toxicity, and is not heat stable. You also discover that it targets liver
,cells. Based on these characteristics, how would you classify this
toxin?
A. superantigen
B. endotoxin
C. exotoxin
D. leukocidin
Answer: C. exotoxin
◉ Which of the following applies to hyaluronidase?
A. it acts as a spreading factor
b. It promotes blood clotting
c. it is an example of an adhesin
D. it is produced by immune cells to target pathogens
Answer: A
◉ Bacteria, fungi, and protozoa often use similar virulence factors
and mechanisms of pathogenicity.
Answer: true
◉ Sickle cell anemia can be classified as which type of disease?
idiopathic
infectious, communicable
,infectious, noncommunicable
noninfectious
Answer: noninfectious
◉ Which of the following is a common secondary fungal disease?
Answers:
giardiasis
histoplasmosis
oral thrush
syphilis
Answer: oral thrush
◉ Which describes the condition in which blood contains actively
dividing bacteria?
Answers:
bacteremia
septicemia
toxemia
viremia
Answer: septicemia
, ◉ Which surface molecules do helminths commonly express that
protect them from the host immune system?
Answers:
fibrins
glycans
hemagglutinins
proteases
Answer: glycans
◉ In the A-B toxin, which subunit is necessary for making the initial
attachment to the host cell?
Answers:
the A subunit
the B subunit
Depending on the toxin, it could be either the A or B subunit.
Neither, because A-B toxins do not function this way.
Answer: the B subunit
◉ During which period of disease is a patient most susceptible to
developing a secondary infection?
Answers:
incubation period
QUESTIONS AND SOLUTIONS GRADED A+
◉ which of the following is a pathogen that could not be identified
by the original Koch's postulates
A. S. aureus
B. P. aeruginosa
C. HIV
D. S. enetrica serovar typhimurium
Answer: C. HIV
◉ Pathogen A has an ID50 of 50 particles, pathogen B has an ID50 of
1,000 particles, and pathogen C has an ID50 of 1 × 106 particles.
Which pathogen is most virulent?
A. pathogen A
B. pathogen B
C. pathogen C
Answer: a. Pathogen A
◉ You have recently identified a new toxin. It is produced by a gram-
negative bacterium. It is composed mostly of protein, has high
toxicity, and is not heat stable. You also discover that it targets liver
,cells. Based on these characteristics, how would you classify this
toxin?
A. superantigen
B. endotoxin
C. exotoxin
D. leukocidin
Answer: C. exotoxin
◉ Which of the following applies to hyaluronidase?
A. it acts as a spreading factor
b. It promotes blood clotting
c. it is an example of an adhesin
D. it is produced by immune cells to target pathogens
Answer: A
◉ Bacteria, fungi, and protozoa often use similar virulence factors
and mechanisms of pathogenicity.
Answer: true
◉ Sickle cell anemia can be classified as which type of disease?
idiopathic
infectious, communicable
,infectious, noncommunicable
noninfectious
Answer: noninfectious
◉ Which of the following is a common secondary fungal disease?
Answers:
giardiasis
histoplasmosis
oral thrush
syphilis
Answer: oral thrush
◉ Which describes the condition in which blood contains actively
dividing bacteria?
Answers:
bacteremia
septicemia
toxemia
viremia
Answer: septicemia
, ◉ Which surface molecules do helminths commonly express that
protect them from the host immune system?
Answers:
fibrins
glycans
hemagglutinins
proteases
Answer: glycans
◉ In the A-B toxin, which subunit is necessary for making the initial
attachment to the host cell?
Answers:
the A subunit
the B subunit
Depending on the toxin, it could be either the A or B subunit.
Neither, because A-B toxins do not function this way.
Answer: the B subunit
◉ During which period of disease is a patient most susceptible to
developing a secondary infection?
Answers:
incubation period
