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HESI A2 Microorganisms & Disease Transmission |
Exam Bank + Infection Control Guide
Table of Contents
Subtopic 1: Fundamentals of Microorganisms and Pathogens .......................................... 2
Subtopic 2: Disease Transmission Mechanisms and Infection Control .............................. 9
Subtopic 3: Bacterial Infections and Clinical Implications .............................................. 17
Subtopic 4: Immune Response to Microorganisms and Vaccination ............................... 25
Subtopic 5: Antibiotics, Resistance, and Stewardship .................................................... 32
Subtopic 6: Infection Prevention and Hospital Protocols ................................................ 40
Subtopic 7: Viral Infections and Control Measures......................................................... 47
Subtopic 8: Emerging and Re-emerging Infectious Diseases........................................... 55
Subtopic 9: Laboratory Diagnosis and Pathogen Identification ....................................... 63
Subtopic 10: Healthcare-Associated Infections (HAIs) and Prevention Strategies ............ 71
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Subtopic 1: Fundamentals of Microorganisms and
Pathogens
Question 1
Which of the following best describes a facultative anaerobe?
A. A microorganism that dies in the presence of oxygen
B. A microorganism that only grows in high oxygen levels
C. A microorganism that can survive with or without oxygen
D. A microorganism that only grows in anaerobic chambers
Correct Answer: C
Rationale: Facultative anaerobes can switch between aerobic respiration when oxygen is
available and anaerobic processes when it is not, allowing them to survive in diverse
environments.
Question 2
Which of the following is a gram-positive cocci commonly found in clusters?
A. Escherichia coli
B. Streptococcus pyogenes
C. Staphylococcus aureus
D. Neisseria gonorrhoeae
Correct Answer: C
Rationale: Staphylococcus aureus is a gram-positive cocci that arranges in clusters,
resembling grape-like structures under the microscope.
Question 3
Which bacterial structure is primarily responsible for antibiotic resistance transfer?
A. Ribosome
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B. Plasmid
C. Endospore
D. Capsule
Correct Answer: B
Rationale: Plasmids often carry genes for antibiotic resistance and can be transferred
between bacteria through conjugation, contributing to resistance spread.
Question 4
Which of the following diseases is caused by a prion?
A. Tuberculosis
B. Creutzfeldt-Jakob disease
C. Influenza
D. Meningitis
Correct Answer: B
Rationale: Prions are misfolded proteins that cause degenerative brain diseases like
Creutzfeldt-Jakob, not caused by bacteria or viruses.
Question 5
What is the main component of the bacterial cell wall in gram-positive organisms?
A. Lipopolysaccharide
B. Phospholipid
C. Peptidoglycan
D. Protein
Correct Answer: C
Rationale: Gram-positive bacteria have thick peptidoglycan layers in their cell walls,
making them retain crystal violet dye during Gram staining.
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Question 6
Which of the following is considered an obligate intracellular pathogen?
A. Chlamydia trachomatis
B. Staphylococcus epidermidis
C. Bacillus anthracis
D. Vibrio cholerae
Correct Answer: A
Rationale: Chlamydia trachomatis cannot replicate outside a host cell and depends
entirely on the intracellular environment.
Question 7
Which structure enables motility in many bacteria?
A. Pilus
B. Capsule
C. Flagellum
D. Nucleoid
Correct Answer: C
Rationale: The flagellum is a whip-like appendage that allows motility by rotating and
propelling the bacterium through its environment.
Question 8
Which statement about viruses is true?
A. They reproduce through binary fission
B. They require a host cell to replicate
C. They have both DNA and RNA
D. They are classified as living organisms
Correct Answer: B
HESI A2 Microorganisms & Disease Transmission |
Exam Bank + Infection Control Guide
Table of Contents
Subtopic 1: Fundamentals of Microorganisms and Pathogens .......................................... 2
Subtopic 2: Disease Transmission Mechanisms and Infection Control .............................. 9
Subtopic 3: Bacterial Infections and Clinical Implications .............................................. 17
Subtopic 4: Immune Response to Microorganisms and Vaccination ............................... 25
Subtopic 5: Antibiotics, Resistance, and Stewardship .................................................... 32
Subtopic 6: Infection Prevention and Hospital Protocols ................................................ 40
Subtopic 7: Viral Infections and Control Measures......................................................... 47
Subtopic 8: Emerging and Re-emerging Infectious Diseases........................................... 55
Subtopic 9: Laboratory Diagnosis and Pathogen Identification ....................................... 63
Subtopic 10: Healthcare-Associated Infections (HAIs) and Prevention Strategies ............ 71
, 2
Subtopic 1: Fundamentals of Microorganisms and
Pathogens
Question 1
Which of the following best describes a facultative anaerobe?
A. A microorganism that dies in the presence of oxygen
B. A microorganism that only grows in high oxygen levels
C. A microorganism that can survive with or without oxygen
D. A microorganism that only grows in anaerobic chambers
Correct Answer: C
Rationale: Facultative anaerobes can switch between aerobic respiration when oxygen is
available and anaerobic processes when it is not, allowing them to survive in diverse
environments.
Question 2
Which of the following is a gram-positive cocci commonly found in clusters?
A. Escherichia coli
B. Streptococcus pyogenes
C. Staphylococcus aureus
D. Neisseria gonorrhoeae
Correct Answer: C
Rationale: Staphylococcus aureus is a gram-positive cocci that arranges in clusters,
resembling grape-like structures under the microscope.
Question 3
Which bacterial structure is primarily responsible for antibiotic resistance transfer?
A. Ribosome
, 3
B. Plasmid
C. Endospore
D. Capsule
Correct Answer: B
Rationale: Plasmids often carry genes for antibiotic resistance and can be transferred
between bacteria through conjugation, contributing to resistance spread.
Question 4
Which of the following diseases is caused by a prion?
A. Tuberculosis
B. Creutzfeldt-Jakob disease
C. Influenza
D. Meningitis
Correct Answer: B
Rationale: Prions are misfolded proteins that cause degenerative brain diseases like
Creutzfeldt-Jakob, not caused by bacteria or viruses.
Question 5
What is the main component of the bacterial cell wall in gram-positive organisms?
A. Lipopolysaccharide
B. Phospholipid
C. Peptidoglycan
D. Protein
Correct Answer: C
Rationale: Gram-positive bacteria have thick peptidoglycan layers in their cell walls,
making them retain crystal violet dye during Gram staining.
, 4
Question 6
Which of the following is considered an obligate intracellular pathogen?
A. Chlamydia trachomatis
B. Staphylococcus epidermidis
C. Bacillus anthracis
D. Vibrio cholerae
Correct Answer: A
Rationale: Chlamydia trachomatis cannot replicate outside a host cell and depends
entirely on the intracellular environment.
Question 7
Which structure enables motility in many bacteria?
A. Pilus
B. Capsule
C. Flagellum
D. Nucleoid
Correct Answer: C
Rationale: The flagellum is a whip-like appendage that allows motility by rotating and
propelling the bacterium through its environment.
Question 8
Which statement about viruses is true?
A. They reproduce through binary fission
B. They require a host cell to replicate
C. They have both DNA and RNA
D. They are classified as living organisms
Correct Answer: B
