Microbiology Final Exam
Jersey College - Comprehensive Review Examination
1. A patient develops swelling, redness, and itching at the site of an insect sting within minutes. This reaction
is mediated by which immunoglobulin?
A. IgG
B. IgM
C. IgA
D. IgE
Correct Answer: D
Rationale: Correct because type I (immediate) hypersensitivity reactions are mediated by IgE antibodies that trigger
mast cell and basophil degranulation, releasing histamine and other mediators.
2. An obligate anaerobe is inadvertently exposed to atmospheric oxygen during a laboratory procedure. Which
of the following best explains why this organism would die?
A. Oxygen deprives the organism of required carbon dioxide for metabolism
B. Oxygen generates toxic superoxide radicals and hydrogen peroxide that the organism cannot detoxify
C. Oxygen competitively inhibits the electron transport chain
D. Oxygen raises the pH above the organism's survival range
Correct Answer: B
Rationale: Correct because obligate anaerobes lack superoxide dismutase and catalase, making them unable to neutralize
toxic reactive oxygen species produced in the presence of oxygen.
3. Schistosoma mansoni has which of the following host relationships?
A. Single host (definitive host only)
B. Two hosts: a definitive human host and an intermediate snail host
C. Three hosts: human, snail, and mosquito
D. Arthropod vector with no intermediate host
Correct Answer: B
Rationale: Correct because Schistosoma species have a complex life cycle requiring a human definitive host (sexual
reproduction) and a freshwater snail intermediate host (asexual reproduction).
4. Taenia saginata (beef tapeworm) is acquired through which mode of transmission?
A. Mosquito bite
B. Ingestion of undercooked beef containing cysticerci
C. Direct skin contact with contaminated soil
D. Inhalation of eggs from contaminated air
Correct Answer: B
Rationale: Correct because T. saginata is transmitted when humans consume raw or undercooked beef containing the
larval stage (cysticerci) of the tapeworm.
,5. Which organelle is considered the powerhouse of the eukaryotic cell and is responsible for ATP production
through oxidative phosphorylation?
A. Golgi apparatus
B. Endoplasmic reticulum
C. Mitochondrion
D. Lysosome
Correct Answer: C
Rationale: Correct because mitochondria are the primary site of oxidative phosphorylation and ATP generation through
the electron transport chain in eukaryotic cells.
6. The lipopolysaccharide (LPS) layer of the outer membrane in gram-negative bacteria is also known as:
A. Peptidoglycan
B. Endotoxin
C. Exotoxin
D. Teichoic acid
Correct Answer: B
Rationale: Correct because the lipid A component of LPS in the outer membrane of gram-negative bacteria functions as
an endotoxin, triggering fever, shock, and disseminated intravascular coagulation.
7. Which of the following diseases is classified as a zoonosis?
A. Tuberculosis
B. Rabies
C. Measles
D. Poliomyelitis
Correct Answer: B
Rationale: Correct because rabies is a zoonotic disease transmitted to humans through the bite of infected mammals,
with bats, dogs, and other wildlife serving as reservoirs.
8. In the Kirby-Bauer disk diffusion method, a zone of inhibition measuring 20 mm is observed around a
vancomycin disk for Staphylococcus aureus. According to standard interpretive criteria, this result would
most likely be reported as:
A. Resistant
B. Intermediate
C. Susceptible
D. Inconclusive
Correct Answer: C
Rationale: Correct because a 20 mm zone of inhibition for vancomycin against S. aureus exceeds the susceptible
breakpoint (typically 15 mm or greater per CLSI standards).
9. In the bacterial genome, a segment of DNA that encodes a functional product such as a protein or RNA
molecule is called a:
A. Operon
, B. Gene
C. Plasmid
D. Promoter
Correct Answer: B
Rationale: Correct because a gene is defined as a segment of DNA that contains the information to produce a functional
product, either a protein or an RNA molecule.
10. Histoplasma capsulatum exists as a mold at room temperature (25 degrees Celsius) and as a yeast at body
temperature (37 degrees Celsius). This temperature-dependent switching is characteristic of which group?
A. Dermatophytes
B. Dimorphic fungi
C. Opportunistic yeasts
D. Commensal fungi
Correct Answer: B
Rationale: Correct because dimorphic fungi switch between a mold form at environmental temperatures and a yeast
form at body temperature, which is central to their pathogenicity.
11. Biosafety Level 3 (BSL-3) is appropriate for work with which type of microorganisms?
A. Non-pathogenic agents with no hazard to humans
B. Moderate-risk agents associated with human disease, with potential for aerosol transmission
C. Highly dangerous exotic agents with high risk of life-threatening disease
D. Agents that cause mild diseases easily treated with over-the-counter medications
Correct Answer: B
Rationale: Correct because BSL-3 is used for indigenous or exotic agents with potential for aerosol transmission and
serious or lethal disease, requiring special ventilation and safety equipment.
12. HIV is classified as a retrovirus because it:
A. Uses RNA as a template to synthesize DNA through the action of reverse transcriptase
B. Contains double-stranded RNA as its genetic material
C. Integrates directly into the host genome without an intermediate DNA step
D. Replicates exclusively in the cytoplasm without entering the nucleus
Correct Answer: A
Rationale: Correct because retroviruses use the enzyme reverse transcriptase to convert their single-stranded RNA
genome into double-stranded DNA, which integrates into the host genome.
13. Which of the following is the most effective method for interrupting the transmission of Clostridioides
difficile in a healthcare setting?
A. Standard alcohol-based hand sanitizers
B. Handwashing with soap and water
C. Wearing surgical masks
D. Placing patients in positive-pressure rooms
Correct Answer: B
Jersey College - Comprehensive Review Examination
1. A patient develops swelling, redness, and itching at the site of an insect sting within minutes. This reaction
is mediated by which immunoglobulin?
A. IgG
B. IgM
C. IgA
D. IgE
Correct Answer: D
Rationale: Correct because type I (immediate) hypersensitivity reactions are mediated by IgE antibodies that trigger
mast cell and basophil degranulation, releasing histamine and other mediators.
2. An obligate anaerobe is inadvertently exposed to atmospheric oxygen during a laboratory procedure. Which
of the following best explains why this organism would die?
A. Oxygen deprives the organism of required carbon dioxide for metabolism
B. Oxygen generates toxic superoxide radicals and hydrogen peroxide that the organism cannot detoxify
C. Oxygen competitively inhibits the electron transport chain
D. Oxygen raises the pH above the organism's survival range
Correct Answer: B
Rationale: Correct because obligate anaerobes lack superoxide dismutase and catalase, making them unable to neutralize
toxic reactive oxygen species produced in the presence of oxygen.
3. Schistosoma mansoni has which of the following host relationships?
A. Single host (definitive host only)
B. Two hosts: a definitive human host and an intermediate snail host
C. Three hosts: human, snail, and mosquito
D. Arthropod vector with no intermediate host
Correct Answer: B
Rationale: Correct because Schistosoma species have a complex life cycle requiring a human definitive host (sexual
reproduction) and a freshwater snail intermediate host (asexual reproduction).
4. Taenia saginata (beef tapeworm) is acquired through which mode of transmission?
A. Mosquito bite
B. Ingestion of undercooked beef containing cysticerci
C. Direct skin contact with contaminated soil
D. Inhalation of eggs from contaminated air
Correct Answer: B
Rationale: Correct because T. saginata is transmitted when humans consume raw or undercooked beef containing the
larval stage (cysticerci) of the tapeworm.
,5. Which organelle is considered the powerhouse of the eukaryotic cell and is responsible for ATP production
through oxidative phosphorylation?
A. Golgi apparatus
B. Endoplasmic reticulum
C. Mitochondrion
D. Lysosome
Correct Answer: C
Rationale: Correct because mitochondria are the primary site of oxidative phosphorylation and ATP generation through
the electron transport chain in eukaryotic cells.
6. The lipopolysaccharide (LPS) layer of the outer membrane in gram-negative bacteria is also known as:
A. Peptidoglycan
B. Endotoxin
C. Exotoxin
D. Teichoic acid
Correct Answer: B
Rationale: Correct because the lipid A component of LPS in the outer membrane of gram-negative bacteria functions as
an endotoxin, triggering fever, shock, and disseminated intravascular coagulation.
7. Which of the following diseases is classified as a zoonosis?
A. Tuberculosis
B. Rabies
C. Measles
D. Poliomyelitis
Correct Answer: B
Rationale: Correct because rabies is a zoonotic disease transmitted to humans through the bite of infected mammals,
with bats, dogs, and other wildlife serving as reservoirs.
8. In the Kirby-Bauer disk diffusion method, a zone of inhibition measuring 20 mm is observed around a
vancomycin disk for Staphylococcus aureus. According to standard interpretive criteria, this result would
most likely be reported as:
A. Resistant
B. Intermediate
C. Susceptible
D. Inconclusive
Correct Answer: C
Rationale: Correct because a 20 mm zone of inhibition for vancomycin against S. aureus exceeds the susceptible
breakpoint (typically 15 mm or greater per CLSI standards).
9. In the bacterial genome, a segment of DNA that encodes a functional product such as a protein or RNA
molecule is called a:
A. Operon
, B. Gene
C. Plasmid
D. Promoter
Correct Answer: B
Rationale: Correct because a gene is defined as a segment of DNA that contains the information to produce a functional
product, either a protein or an RNA molecule.
10. Histoplasma capsulatum exists as a mold at room temperature (25 degrees Celsius) and as a yeast at body
temperature (37 degrees Celsius). This temperature-dependent switching is characteristic of which group?
A. Dermatophytes
B. Dimorphic fungi
C. Opportunistic yeasts
D. Commensal fungi
Correct Answer: B
Rationale: Correct because dimorphic fungi switch between a mold form at environmental temperatures and a yeast
form at body temperature, which is central to their pathogenicity.
11. Biosafety Level 3 (BSL-3) is appropriate for work with which type of microorganisms?
A. Non-pathogenic agents with no hazard to humans
B. Moderate-risk agents associated with human disease, with potential for aerosol transmission
C. Highly dangerous exotic agents with high risk of life-threatening disease
D. Agents that cause mild diseases easily treated with over-the-counter medications
Correct Answer: B
Rationale: Correct because BSL-3 is used for indigenous or exotic agents with potential for aerosol transmission and
serious or lethal disease, requiring special ventilation and safety equipment.
12. HIV is classified as a retrovirus because it:
A. Uses RNA as a template to synthesize DNA through the action of reverse transcriptase
B. Contains double-stranded RNA as its genetic material
C. Integrates directly into the host genome without an intermediate DNA step
D. Replicates exclusively in the cytoplasm without entering the nucleus
Correct Answer: A
Rationale: Correct because retroviruses use the enzyme reverse transcriptase to convert their single-stranded RNA
genome into double-stranded DNA, which integrates into the host genome.
13. Which of the following is the most effective method for interrupting the transmission of Clostridioides
difficile in a healthcare setting?
A. Standard alcohol-based hand sanitizers
B. Handwashing with soap and water
C. Wearing surgical masks
D. Placing patients in positive-pressure rooms
Correct Answer: B
