BIOL 271 MICROBIOLOGY W/ LAB MODULE 5 EXAM REVIEW | LOCKDOWN BROWSER | PORTAGE
LEARNING
Questions 1–100+
#### SECTION 1: UNIVERSAL PRECAUTIONS & LABORATORY SAFETY (Questions 1–10)
1. The concept of treating all samples, whether known or unknown, as potentially hazardous (or
pathogenic) materials is known as:
A) Standard isolation
B) Universal precautions
C) Aseptic technique
D) Biosafety level 1
Answer B: Universal precautions
Rationale: Universal precautions means any and all samples, whether known or unknown, are to be treated
as potentially hazardous (or pathogenic) materials.
2. A researcher is working with an unknown microbial sample in a clinical laboratory. Which of the
following represents the safest approach?
A) Treat the sample as non-pathogenic until proven otherwise
B) Treat the sample using universal precautions at all times
C) Only use gloves if the sample appears contaminated
D) Work in an open laboratory bench without containment
Answer B: Treat the sample using universal precautions at all times
Rationale: Universal precautions require treating ALL samples as potentially hazardous, regardless of their
suspected origin.
3. Which of the following is NOT a component of universal precautions in a microbiology laboratory?
A) Wearing gloves when handling samples
B) Proper disposal of biohazardous waste
C) Eating and drinking in the laboratory is permitted if samples are sealed
D) Hand washing after removing gloves
,Answer C: Eating and drinking in the laboratory is permitted if samples are sealed
Rationale: Eating and drinking are never permitted in the laboratory, regardless of sample status.
4. A researcher is analyzing an unknown sample and must determine motility and Gram status. The
liquid sample cannot be divided. Which should be determined first and why?
A) Motility first, because Gram staining requires heat fixation which would kill the organism and prevent
motility observation
B) Gram status first, because motility can be determined after Gram staining
C) Either can be determined first as the order does not matter
D) Gram status first, because motility requires special equipment not available
Answer A: Motility first, because Gram staining requires heat fixation which would kill the organism
and prevent motility observation
Rationale: Motility must be determined first because Gram staining requires heat fixation, which kills the
organism and makes motility observation impossible.
5. A researcher observes an unknown microbial sample. List at least 3 observations that should be
noted.
A) Size and shape, motility, Gram status
B) Color only and temperature
C) Weight and volume only
D) Age of the sample and source
Answer A: Size and shape, motility, Gram status
Rationale: A researcher would note: size and shape, any observable motility, Gram status (positive or
negative), presence of any chemical reactions, and color changes.
6. A microbiologist is working with a sample that is known to contain a highly pathogenic organism.
Which biosafety level is most appropriate?
A) BSL-1
B) BSL-3 or BSL-4 depending on the organism
C) BSL-2 only
D) No special precautions are needed
Answer B: BSL-3 or BSL-4 depending on the organism
,Rationale: The biosafety level depends on the specific organism and its pathogenicity; highly pathogenic
organisms require BSL-3 or BSL-4 containment.
7. True or False: Universal precautions only apply to samples that are visibly contaminated or known
to be from infected patients.
A) True
B) False
C) True
D) True
Answer B: False
Rationale: Universal precautions apply to ALL samples, whether known or unknown, regardless of visible
contamination or patient history.
8. Which of the following is the correct order for donning personal protective equipment (PPE) in a
microbiology lab?
A) Gloves, gown, mask, goggles
B) Gown, mask, goggles, gloves
C) Mask, gloves, gown, goggles
D) Goggles, gloves, gown, mask
Answer B: Gown, mask, goggles, gloves
Rationale: The correct order for donning PPE is gown first, then mask, then goggles, then gloves.
9. A researcher accidentally spills a microbial culture on the laboratory bench. What is the FIRST
action to take?
A) Notify the supervisor and clean the spill with appropriate disinfectant
B) Wipe it up with a paper towel
C) Leave it to air dry
D) Cover it with a sterile cloth
Answer A: Notify the supervisor and clean the spill with appropriate disinfectant
Rationale: Spills must be reported immediately and cleaned with appropriate disinfectant following
institutional protocols.
, 10. Which of the following is an example of a chemical hazard in a microbiology laboratory?
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A) Bacterial cultures
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B) Fixatives and staining reagents
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C) Needles and scalpels
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D) Glass slides
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Answer B: Fixatives and staining reagents j0 j0 j0 j0 j0
Rationale: Chemical hazards include fixatives (e.g., formaldehyde) and staining reagents (e.g., crystal
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j0 violet, safranin). --- #### SECTION 2: MICROBIAL IDENTIFICATION & LABORATORY TECHNIQUES
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j0 (Questions 11–30) j0
11. While observing an unknown sample of limited amounts, a researcher must determine motility
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j0 and Gram status using the same sample. What would you determine first and why?
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A) Motility because Gram staining requires the sample be fixed which would kill the organism and then
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j0 you can't observe motility
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B) Gram status because it provides more information
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C) Either can be done first
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D) Neither can be determined from the same sample
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Answer A: Motility because Gram staining requires the sample be fixed which would kill the
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j0 organism and then you can't observe motility j0 j0 j0 j0 j0 j0
Rationale: Motility must be assessed first using a wet mount, as heat fixation for Gram staining kills the
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j0 organism.
12. A facultative anaerobe is a microorganism capable of growth under what conditions?
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A) Aerobic and anaerobic conditions
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B) Only aerobic conditions
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C) Only anaerobic conditions
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D) Only microaerophilic conditions
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Answer A: Aerobic and anaerobic conditions j0 j0 j0 j0 j0
Rationale: A facultative anaerobe can grow under both aerobic and anaerobic conditions.
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13. Streptococcus is catalase negative. Would it survive in the presence of peroxides? Why?
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A) No, because it is unable to break down peroxides (catalase negative)
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B) Yes, because it produces catalase
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LEARNING
Questions 1–100+
#### SECTION 1: UNIVERSAL PRECAUTIONS & LABORATORY SAFETY (Questions 1–10)
1. The concept of treating all samples, whether known or unknown, as potentially hazardous (or
pathogenic) materials is known as:
A) Standard isolation
B) Universal precautions
C) Aseptic technique
D) Biosafety level 1
Answer B: Universal precautions
Rationale: Universal precautions means any and all samples, whether known or unknown, are to be treated
as potentially hazardous (or pathogenic) materials.
2. A researcher is working with an unknown microbial sample in a clinical laboratory. Which of the
following represents the safest approach?
A) Treat the sample as non-pathogenic until proven otherwise
B) Treat the sample using universal precautions at all times
C) Only use gloves if the sample appears contaminated
D) Work in an open laboratory bench without containment
Answer B: Treat the sample using universal precautions at all times
Rationale: Universal precautions require treating ALL samples as potentially hazardous, regardless of their
suspected origin.
3. Which of the following is NOT a component of universal precautions in a microbiology laboratory?
A) Wearing gloves when handling samples
B) Proper disposal of biohazardous waste
C) Eating and drinking in the laboratory is permitted if samples are sealed
D) Hand washing after removing gloves
,Answer C: Eating and drinking in the laboratory is permitted if samples are sealed
Rationale: Eating and drinking are never permitted in the laboratory, regardless of sample status.
4. A researcher is analyzing an unknown sample and must determine motility and Gram status. The
liquid sample cannot be divided. Which should be determined first and why?
A) Motility first, because Gram staining requires heat fixation which would kill the organism and prevent
motility observation
B) Gram status first, because motility can be determined after Gram staining
C) Either can be determined first as the order does not matter
D) Gram status first, because motility requires special equipment not available
Answer A: Motility first, because Gram staining requires heat fixation which would kill the organism
and prevent motility observation
Rationale: Motility must be determined first because Gram staining requires heat fixation, which kills the
organism and makes motility observation impossible.
5. A researcher observes an unknown microbial sample. List at least 3 observations that should be
noted.
A) Size and shape, motility, Gram status
B) Color only and temperature
C) Weight and volume only
D) Age of the sample and source
Answer A: Size and shape, motility, Gram status
Rationale: A researcher would note: size and shape, any observable motility, Gram status (positive or
negative), presence of any chemical reactions, and color changes.
6. A microbiologist is working with a sample that is known to contain a highly pathogenic organism.
Which biosafety level is most appropriate?
A) BSL-1
B) BSL-3 or BSL-4 depending on the organism
C) BSL-2 only
D) No special precautions are needed
Answer B: BSL-3 or BSL-4 depending on the organism
,Rationale: The biosafety level depends on the specific organism and its pathogenicity; highly pathogenic
organisms require BSL-3 or BSL-4 containment.
7. True or False: Universal precautions only apply to samples that are visibly contaminated or known
to be from infected patients.
A) True
B) False
C) True
D) True
Answer B: False
Rationale: Universal precautions apply to ALL samples, whether known or unknown, regardless of visible
contamination or patient history.
8. Which of the following is the correct order for donning personal protective equipment (PPE) in a
microbiology lab?
A) Gloves, gown, mask, goggles
B) Gown, mask, goggles, gloves
C) Mask, gloves, gown, goggles
D) Goggles, gloves, gown, mask
Answer B: Gown, mask, goggles, gloves
Rationale: The correct order for donning PPE is gown first, then mask, then goggles, then gloves.
9. A researcher accidentally spills a microbial culture on the laboratory bench. What is the FIRST
action to take?
A) Notify the supervisor and clean the spill with appropriate disinfectant
B) Wipe it up with a paper towel
C) Leave it to air dry
D) Cover it with a sterile cloth
Answer A: Notify the supervisor and clean the spill with appropriate disinfectant
Rationale: Spills must be reported immediately and cleaned with appropriate disinfectant following
institutional protocols.
, 10. Which of the following is an example of a chemical hazard in a microbiology laboratory?
j0 j0 j0 j0 j0 j0 j0 j0 j0 j0 j0 j0 j0 j0 j0
A) Bacterial cultures
j0 j0
B) Fixatives and staining reagents
j0 j0 j0 j0
C) Needles and scalpels
j0 j0 j0
D) Glass slides
j0 j0
Answer B: Fixatives and staining reagents j0 j0 j0 j0 j0
Rationale: Chemical hazards include fixatives (e.g., formaldehyde) and staining reagents (e.g., crystal
j0 j0 j0 j0 j0 j0 j0 j0 j0 j0 j0
j0 violet, safranin). --- #### SECTION 2: MICROBIAL IDENTIFICATION & LABORATORY TECHNIQUES
j0 j0 j0 j0 j0 j0 j0 j0 j0 j0
j0 (Questions 11–30) j0
11. While observing an unknown sample of limited amounts, a researcher must determine motility
j0 j0 j0 j0 j0 j0 j0 j0 j0 j0 j0 j0 j0
j0 and Gram status using the same sample. What would you determine first and why?
j0 j0 j0 j0 j0 j0 j0 j0 j0 j0 j0 j0 j0
A) Motility because Gram staining requires the sample be fixed which would kill the organism and then
j0 j0 j0 j0 j0 j0 j0 j0 j0 j0 j0 j0 j0 j0 j0 j0
j0 you can't observe motility
j0 j0 j0
B) Gram status because it provides more information
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C) Either can be done first
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D) Neither can be determined from the same sample
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Answer A: Motility because Gram staining requires the sample be fixed which would kill the
j0 j0 j0 j0 j0 j0 j0 j0 j0 j0 j0 j0 j0 j0
j0 organism and then you can't observe motility j0 j0 j0 j0 j0 j0
Rationale: Motility must be assessed first using a wet mount, as heat fixation for Gram staining kills the
j0 j0 j0 j0 j0 j0 j0 j0 j0 j0 j0 j0 j0 j0 j0 j0 j0
j0 organism.
12. A facultative anaerobe is a microorganism capable of growth under what conditions?
j0 j0 j0 j0 j0 j0 j0 j0 j0 j0 j0 j0
A) Aerobic and anaerobic conditions
j0 j0 j0 j0
B) Only aerobic conditions
j0 j0 j0
C) Only anaerobic conditions
j0 j0 j0
D) Only microaerophilic conditions
j0 j0 j0
Answer A: Aerobic and anaerobic conditions j0 j0 j0 j0 j0
Rationale: A facultative anaerobe can grow under both aerobic and anaerobic conditions.
j0 j0 j0 j0 j0 j0 j0 j0 j0 j0 j0
13. Streptococcus is catalase negative. Would it survive in the presence of peroxides? Why?
j0 j0 j0 j0 j0 j0 j0 j0 j0 j0 j0 j0 j0
A) No, because it is unable to break down peroxides (catalase negative)
j0 j0 j0 j0 j0 j0 j0 j0 j0 j0 j0
B) Yes, because it produces catalase
j0 j0 j0 j0 j0
