BIOD 171 Essential Microbiology Module 5 Exam – Portage Learning (2026) Actual Questions with Verified Answers | Take & Pass the Exam

BIOD 171 Essential Microbiology Module 5 Exam – Portage Learning (2026) Actual Questions with Verified
Answers | Take & Pass the Exam


Questions 1–250
Section 1: Universal Precautions, Biosafety & PPE (Questions 1–25)


1. The concept of treating all samples, whether known or unknown, as potentially hazardous (or
pathogenic) materials is known as _____.
A) Standard precautions
B) Universal precautions
C) Contact precautions
D) Airborne precautions
Answer B: Universal precautions
Rationale: Universal precautions require treating all biological samples as potentially infectious regardless
of perceived status.




2. Define the concept of universal precautions.
A) Treat all samples, whether known or unknown, as potentially hazardous or pathogenic materials
B) Only treat known pathogenic samples with care
C) Treat samples based on patient history
D) Only use PPE for blood samples
Answer A: Treat all samples, whether known or unknown, as potentially hazardous or pathogenic
materials
Rationale: Universal precautions assume all biological materials may contain infectious agents.




3. Universal precautions were developed primarily to minimize risk of exposure to:
A) All microorganisms
B) Bloodborne pathogens
C) Airborne pathogens
D) Foodborne pathogens
Answer B: Bloodborne pathogens

,Rationale: Universal precautions focus on blood and certain body fluids as potential sources of bloodborne
pathogens.




4. Which of the following is an example of personal protective equipment (PPE) used in the
microbiology laboratory?
A) Gloves, lab coat, and safety goggles
B) Only gloves
C) Only a lab coat
D) Only safety goggles
Answer A: Gloves, lab coat, and safety goggles
Rationale: PPE includes gloves, lab coats, and eye protection to prevent exposure to infectious materials.




5. Standard precautions in healthcare settings include:
A) Hand hygiene, PPE, and safe injection practices
B) Only hand hygiene
C) Only PPE
D) Only isolation
Answer A: Hand hygiene, PPE, and safe injection practices
Rationale: Standard precautions combine universal precautions with body substance isolation.




6. The chain of infection includes:
A) Infectious agent, reservoir, portal of exit, mode of transmission, portal of entry, susceptible host
B) Only infectious agent and host
C) Only reservoir and transmission
D) Only portal of entry and exit
Answer A: Infectious agent, reservoir, portal of exit, mode of transmission, portal of entry,
susceptible host
Rationale: All six links must be present for infection to occur.




7. Which of the following is the most common portal of entry for human pathogens?
A) Skin
B) Mucous membranes of the respiratory tract

,C) Gastrointestinal tract
D) Urinary tract
Answer B: Mucous membranes of the respiratory tract
Rationale: The respiratory tract is the most frequent entry point for pathogens.




8. True or False: Universal precautions only apply to blood samples.
A) True
B) False
Answer B: False
Rationale: Universal precautions apply to all human blood and certain body fluids, but the principle extends
to all biological samples in the lab.




9. The five steps of infection include:
A) Entry, adhesion, invasion, multiplication, and spread
B) Entry, adhesion, and invasion only
C) Invasion, multiplication, and spread only
D) Adhesion, invasion, and multiplication only
Answer A: Entry, adhesion, invasion, multiplication, and spread
Rationale: These steps describe the pathogenesis process.




10. Pathogenicity is defined as:
A) The ability of a microorganism to cause disease
B) The severity of disease
C) The ability to produce toxins
D) The ability to survive outside the host
Answer A: The ability of a microorganism to cause disease
Rationale: Pathogenicity is the capacity to cause disease.




11. Virulence refers to:
A) The degree of pathogenicity or severity of disease
B) The ability to enter the host
C) The ability to evade the immune system

, D) The ability to produce enzymes
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Answer A: The degree of pathogenicity or severity of disease
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Rationale: Virulence measures how severe a disease a pathogen can cause.
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12. An exotoxin is:
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A) A protein toxin released by living bacteria
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B) A toxin released only upon cell death
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C) A component of the bacterial cell wall
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D) A toxin that only affects the nervous system
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Answer A: A protein toxin released by living bacteria
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Rationale: Exotoxins are secreted by living bacteria and are highly potent.
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13. An endotoxin is:
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A) A protein toxin released by living bacteria
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B) A lipopolysaccharide component of the Gram-negative cell wall
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C) A toxin that only affects the gastrointestinal tract
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D) A toxin produced by Gram-positive bacteria
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Answer B: A lipopolysaccharide component of the Gram-negative cell wall
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Rationale: Endotoxins are released when Gram-negative bacteria lyse.
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14. Which of the following is a characteristic of exotoxins?
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A) They are heat-labile proteins
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B) They are heat-stable
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C) They are not immunogenic
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D) They are part of the cell wall
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Answer A: They are heat-labile proteins
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Rationale: Exotoxins are typically proteins that can be inactivated by heat.
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15. Which of the following is a characteristic of endotoxins?
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A) They are proteins
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B) They are lipopolysaccharides
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C) They are secreted by living cells
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