PORTAGE LEARNING
Bachelor of Science in Nursing (BSN)
BIOL 271 / BIOL 271 Module 5 — Microbiology
Academic Year: 2026/2027 Pathogenesis & Bacterial Infections · Question Bank
NCLEX-style
Q1 What is an endospore?
A. A small, rounded, thick-walled, resting cell that forms inside a bacterial cell
B. A vegetative cell that is actively growing
C. A fungal reproductive structure
D. A viral capsid
CORRECT ANSWER:
A. A small, rounded, thick-walled, resting cell that forms inside a bacterial cell
— RATIONALE
An endospore is a dormant, metabolically inactive structure formed by certain bacteria
(e.g., Bacillus, Clostridium) in response to environmental stressors. It is highly resistant to
heat, desiccation, and disinfectants. Vegetative cells are the active growing forms.
,Q2 What are universal precautions?
A. Used only for known infectious samples
B. Used for all unknown samples; treat all as pathogenic/hazardous
C. Only required for bloodborne pathogens
D. Used exclusively in surgical settings
CORRECT ANSWER:
B. Used for all unknown samples; treat all as pathogenic/hazardous
— RATIONALE
Universal precautions are infection control guidelines that assume all human blood and
body fluids are potentially infectious. They require treating all unknown samples as
hazardous and using appropriate PPE to prevent exposure.
Q3 What is pathogenicity?
A. The ability of a microbe to cause disease
B. The ease with which a pathogen infects a host
C. The degree of illness caused by a pathogen
D. The ability to evade the immune system
CORRECT ANSWER: A. The ability of a microbe to cause disease
— RATIONALE
Pathogenicity is the intrinsic ability of a microorganism to cause disease. Virulence, in
contrast, refers to the degree of pathogenicity or the ease with which an organism causes
disease.
,Q4 What is sepsis?
A. A localized infection at the site of entry
B. A bodywide inflammatory response to an infection and/or toxins released by the
pathogen
C. An infection of the blood only
D. A viral infection of the respiratory tract
CORRECT ANSWER:
B. A bodywide inflammatory response to an infection and/or toxins released by
the pathogen
— RATIONALE
Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to
infection. It ranges from mild (fever, tachycardia) to severe with organ failure and septic
shock.
Q5 What are the 5 steps to infection in order?
A. Entry, attachment, invasion, evasion, exit and transmission
B. Attachment, entry, invasion, evasion, exit
C. Invasion, attachment, entry, evasion, transmission
D. Entry, evasion, attachment, invasion, exit
CORRECT ANSWER:
A. Entry, attachment, invasion, evasion, exit and transmission
— RATIONALE
The five steps of infection are: 1) Entry through portals of entry; 2) Attachment to host
tissues; 3) Invasion of deeper tissues; 4) Evasion of immune defenses; 5) Exit and
transmission to a new host.
, Q6 What are the characteristics of Streptococcus?
A. Gram positive, cocci, tends to link in chains, catalase negative
B. Gram negative, bacilli, catalase positive
C. Gram positive, cocci in clusters, catalase positive
D. Gram negative, spirochete, oxidase positive
CORRECT ANSWER:
A. Gram positive, cocci, tends to link in chains, catalase negative
— RATIONALE
Streptococci are gram-positive cocci that arrange in chains. They are catalase-negative
(unlike staphylococci), and are often cultured on blood agar to observe hemolytic
patterns.
Q7 What type of hemolysis does Streptococcus pneumoniae exhibit on blood
agar?
A. Beta hemolysis (complete lysis, clear zone)
B. Alpha hemolysis (partial lysis, green/brown discoloration)
C. Gamma hemolysis (no lysis)
D. Delta hemolysis
CORRECT ANSWER:
B. Alpha hemolysis (partial lysis, green/brown discoloration)
— RATIONALE
S. pneumoniae is alpha-hemolytic, producing a greenish-brown discoloration on blood
agar due to partial red blood cell lysis. S. pyogenes is beta-hemolytic (clear zone), and E.
faecalis is gamma-hemolytic (no lysis).
Bachelor of Science in Nursing (BSN)
BIOL 271 / BIOL 271 Module 5 — Microbiology
Academic Year: 2026/2027 Pathogenesis & Bacterial Infections · Question Bank
NCLEX-style
Q1 What is an endospore?
A. A small, rounded, thick-walled, resting cell that forms inside a bacterial cell
B. A vegetative cell that is actively growing
C. A fungal reproductive structure
D. A viral capsid
CORRECT ANSWER:
A. A small, rounded, thick-walled, resting cell that forms inside a bacterial cell
— RATIONALE
An endospore is a dormant, metabolically inactive structure formed by certain bacteria
(e.g., Bacillus, Clostridium) in response to environmental stressors. It is highly resistant to
heat, desiccation, and disinfectants. Vegetative cells are the active growing forms.
,Q2 What are universal precautions?
A. Used only for known infectious samples
B. Used for all unknown samples; treat all as pathogenic/hazardous
C. Only required for bloodborne pathogens
D. Used exclusively in surgical settings
CORRECT ANSWER:
B. Used for all unknown samples; treat all as pathogenic/hazardous
— RATIONALE
Universal precautions are infection control guidelines that assume all human blood and
body fluids are potentially infectious. They require treating all unknown samples as
hazardous and using appropriate PPE to prevent exposure.
Q3 What is pathogenicity?
A. The ability of a microbe to cause disease
B. The ease with which a pathogen infects a host
C. The degree of illness caused by a pathogen
D. The ability to evade the immune system
CORRECT ANSWER: A. The ability of a microbe to cause disease
— RATIONALE
Pathogenicity is the intrinsic ability of a microorganism to cause disease. Virulence, in
contrast, refers to the degree of pathogenicity or the ease with which an organism causes
disease.
,Q4 What is sepsis?
A. A localized infection at the site of entry
B. A bodywide inflammatory response to an infection and/or toxins released by the
pathogen
C. An infection of the blood only
D. A viral infection of the respiratory tract
CORRECT ANSWER:
B. A bodywide inflammatory response to an infection and/or toxins released by
the pathogen
— RATIONALE
Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to
infection. It ranges from mild (fever, tachycardia) to severe with organ failure and septic
shock.
Q5 What are the 5 steps to infection in order?
A. Entry, attachment, invasion, evasion, exit and transmission
B. Attachment, entry, invasion, evasion, exit
C. Invasion, attachment, entry, evasion, transmission
D. Entry, evasion, attachment, invasion, exit
CORRECT ANSWER:
A. Entry, attachment, invasion, evasion, exit and transmission
— RATIONALE
The five steps of infection are: 1) Entry through portals of entry; 2) Attachment to host
tissues; 3) Invasion of deeper tissues; 4) Evasion of immune defenses; 5) Exit and
transmission to a new host.
, Q6 What are the characteristics of Streptococcus?
A. Gram positive, cocci, tends to link in chains, catalase negative
B. Gram negative, bacilli, catalase positive
C. Gram positive, cocci in clusters, catalase positive
D. Gram negative, spirochete, oxidase positive
CORRECT ANSWER:
A. Gram positive, cocci, tends to link in chains, catalase negative
— RATIONALE
Streptococci are gram-positive cocci that arrange in chains. They are catalase-negative
(unlike staphylococci), and are often cultured on blood agar to observe hemolytic
patterns.
Q7 What type of hemolysis does Streptococcus pneumoniae exhibit on blood
agar?
A. Beta hemolysis (complete lysis, clear zone)
B. Alpha hemolysis (partial lysis, green/brown discoloration)
C. Gamma hemolysis (no lysis)
D. Delta hemolysis
CORRECT ANSWER:
B. Alpha hemolysis (partial lysis, green/brown discoloration)
— RATIONALE
S. pneumoniae is alpha-hemolytic, producing a greenish-brown discoloration on blood
agar due to partial red blood cell lysis. S. pyogenes is beta-hemolytic (clear zone), and E.
faecalis is gamma-hemolytic (no lysis).
