Galen College NUR 155 Microbiology
Units 1–11 Quiz Bundle | Complete
Questions & Answers | 2026 Updated
| 100% Correct.
1. A pathogenic microbe is best defined as:
Correct Answer: Disease-causing
Rationale: The term “pathogenic” literally means
“disease-producing.” A microbe is classified as pathogenic if
it has the ability to invade a host and cause an infectious
disease. Pathogenicity is a complex trait that involves the
microbe’s ability to evade the host’s immune system,
produce toxins, and multiply within the host’s tissues.
2. Which of the following is NOT a domain of life?
Options: A) Eubacteria B) Archaea C) Protista D) Eukarya
Correct Answer: C) Protista
Rationale: The three-domain system includes Eubacteria
(true bacteria), Archaea, and Eukarya. Protista is a kingdom
within the Eukarya domain, not a separate domain itself.
Understanding these domains is critical for classifying
microorganisms and predicting their characteristics, such as
cell wall composition and metabolic pathways.
,3. A patient is diagnosed with an infection caused by a
microbe that has a peptidoglycan cell wall and is unicellular.
To which domain does this microbe belong?
Options: A) Archaea B) Eubacteria C) Eukarya D) Viruses
Correct Answer: B) Eubacteria
Rationale: Peptidoglycan is a unique polymer found only in
the cell walls of Eubacteria (true bacteria). Archaea lack
peptidoglycan, and Eukarya (fungi, protozoa, plants, animals)
have different cell wall compositions (e.g., chitin in fungi,
cellulose in plants) or no cell wall at all. Viruses are acellular
and do not have a cell wall.
4. A nurse is educating a patient about the chain of infection.
The nurse correctly states that the “reservoir” is:
Options: A) How the microorganism leaves the reservoir B)
Where the microorganism lives and multiplies C) How the
microorganism enters a new host D) A person at risk for
infection
Correct Answer: B) Where the microorganism lives and
multiplies
Rationale: The reservoir is the natural habitat where an
infectious agent normally lives, grows, and multiplies.
Common reservoirs include humans (e.g., a carrier of Staph
aureus), animals (zoonotic reservoirs), and environmental
sources (e.g., soil harboring Clostridium tetani). Breaking the
chain at the reservoir involves measures such as treating
infected patients, isolating carriers, or eliminating
environmental sources.
,5. A nurse is caring for a patient with an infected wound. The
nurse knows the first line of defense against infection
includes all of the following EXCEPT:
Options: A) Intact skin B) Inflammatory response C) Mucous
membranes D) Cilia in the nasal passages
Correct Answer: B) Inflammatory response
Rationale: The body’s defense system is organized into three
lines. First-line defenses are physical and chemical barriers
that prevent pathogen entry, including intact skin, mucous
membranes, cilia, tears, and gastric acid. The inflammatory
response (second line) is activated only after these barriers
are breached and involves vascular changes, phagocyte
recruitment, and fever. Teaching patients to maintain healthy
skin and mucous membranes is a key nursing intervention for
infection prevention.
6. A patient asks the nurse, “What is the most important thing
I can do to prevent getting an infection at home?” Which of
the following is the nurse’s best response?
Options: A) “Take a daily multivitamin.” B) “Get an influenza
vaccine every year.” C) “Use an alcohol-based hand sanitizer
frequently.” D) “Wash your hands properly with soap and
water.”
Correct Answer: D) “Wash your hands properly with soap
and water.”
Rationale: Hand hygiene is consistently identified as the
single most effective infection control measure in both
healthcare and community settings. Proper handwashing
with soap and water removes transient microorganisms,
, prevents cross-contamination, and reduces the incidence of
healthcare-associated and community-acquired infections.
While other measures (vaccination, sanitizers, nutrition) are
also important, they do not replace the fundamental
importance of handwashing.
7. During shift report, the nurse learns a patient is on “contact
precautions.” Which of the following sets of personal
protective equipment (PPE) is appropriate for entering this
patient’s room?
Options: A) Gloves only B) Gloves and mask C) Gloves and
gown D) Gloves, gown, and N95 respirator
Correct Answer: C) Gloves and gown
Rationale: Contact precautions are used for patients with
infections spread by direct or indirect contact (e.g., C. difficile,
MRSA, VRE, scabies). The required PPE includes gloves and a
gown upon room entry. A mask (with or without eye
protection) is added only if splashes or sprays are anticipated.
An N95 respirator is required for airborne precautions (e.g.,
TB, measles). These precautions are a key part of
transmission-based isolation and are essential for preventing
the spread of multidrug-resistant organisms in healthcare
settings.
8. A nurse is setting up a patient’s room for “airborne
precautions.” Which of the following room requirements is a
priority?
Options: A) Private room with negative air pressure B) Private
room that can be coupled with another patient if beds are 3
Units 1–11 Quiz Bundle | Complete
Questions & Answers | 2026 Updated
| 100% Correct.
1. A pathogenic microbe is best defined as:
Correct Answer: Disease-causing
Rationale: The term “pathogenic” literally means
“disease-producing.” A microbe is classified as pathogenic if
it has the ability to invade a host and cause an infectious
disease. Pathogenicity is a complex trait that involves the
microbe’s ability to evade the host’s immune system,
produce toxins, and multiply within the host’s tissues.
2. Which of the following is NOT a domain of life?
Options: A) Eubacteria B) Archaea C) Protista D) Eukarya
Correct Answer: C) Protista
Rationale: The three-domain system includes Eubacteria
(true bacteria), Archaea, and Eukarya. Protista is a kingdom
within the Eukarya domain, not a separate domain itself.
Understanding these domains is critical for classifying
microorganisms and predicting their characteristics, such as
cell wall composition and metabolic pathways.
,3. A patient is diagnosed with an infection caused by a
microbe that has a peptidoglycan cell wall and is unicellular.
To which domain does this microbe belong?
Options: A) Archaea B) Eubacteria C) Eukarya D) Viruses
Correct Answer: B) Eubacteria
Rationale: Peptidoglycan is a unique polymer found only in
the cell walls of Eubacteria (true bacteria). Archaea lack
peptidoglycan, and Eukarya (fungi, protozoa, plants, animals)
have different cell wall compositions (e.g., chitin in fungi,
cellulose in plants) or no cell wall at all. Viruses are acellular
and do not have a cell wall.
4. A nurse is educating a patient about the chain of infection.
The nurse correctly states that the “reservoir” is:
Options: A) How the microorganism leaves the reservoir B)
Where the microorganism lives and multiplies C) How the
microorganism enters a new host D) A person at risk for
infection
Correct Answer: B) Where the microorganism lives and
multiplies
Rationale: The reservoir is the natural habitat where an
infectious agent normally lives, grows, and multiplies.
Common reservoirs include humans (e.g., a carrier of Staph
aureus), animals (zoonotic reservoirs), and environmental
sources (e.g., soil harboring Clostridium tetani). Breaking the
chain at the reservoir involves measures such as treating
infected patients, isolating carriers, or eliminating
environmental sources.
,5. A nurse is caring for a patient with an infected wound. The
nurse knows the first line of defense against infection
includes all of the following EXCEPT:
Options: A) Intact skin B) Inflammatory response C) Mucous
membranes D) Cilia in the nasal passages
Correct Answer: B) Inflammatory response
Rationale: The body’s defense system is organized into three
lines. First-line defenses are physical and chemical barriers
that prevent pathogen entry, including intact skin, mucous
membranes, cilia, tears, and gastric acid. The inflammatory
response (second line) is activated only after these barriers
are breached and involves vascular changes, phagocyte
recruitment, and fever. Teaching patients to maintain healthy
skin and mucous membranes is a key nursing intervention for
infection prevention.
6. A patient asks the nurse, “What is the most important thing
I can do to prevent getting an infection at home?” Which of
the following is the nurse’s best response?
Options: A) “Take a daily multivitamin.” B) “Get an influenza
vaccine every year.” C) “Use an alcohol-based hand sanitizer
frequently.” D) “Wash your hands properly with soap and
water.”
Correct Answer: D) “Wash your hands properly with soap
and water.”
Rationale: Hand hygiene is consistently identified as the
single most effective infection control measure in both
healthcare and community settings. Proper handwashing
with soap and water removes transient microorganisms,
, prevents cross-contamination, and reduces the incidence of
healthcare-associated and community-acquired infections.
While other measures (vaccination, sanitizers, nutrition) are
also important, they do not replace the fundamental
importance of handwashing.
7. During shift report, the nurse learns a patient is on “contact
precautions.” Which of the following sets of personal
protective equipment (PPE) is appropriate for entering this
patient’s room?
Options: A) Gloves only B) Gloves and mask C) Gloves and
gown D) Gloves, gown, and N95 respirator
Correct Answer: C) Gloves and gown
Rationale: Contact precautions are used for patients with
infections spread by direct or indirect contact (e.g., C. difficile,
MRSA, VRE, scabies). The required PPE includes gloves and a
gown upon room entry. A mask (with or without eye
protection) is added only if splashes or sprays are anticipated.
An N95 respirator is required for airborne precautions (e.g.,
TB, measles). These precautions are a key part of
transmission-based isolation and are essential for preventing
the spread of multidrug-resistant organisms in healthcare
settings.
8. A nurse is setting up a patient’s room for “airborne
precautions.” Which of the following room requirements is a
priority?
Options: A) Private room with negative air pressure B) Private
room that can be coupled with another patient if beds are 3
