BIOL 271 Microbiology w/ Lab Module 5 Exam Review | LockDown
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250 original, exam-style practice questions built from publicly visible Module 5 topic coverage. Correct choices are marked inline with a green tick in a box.
This is not an official Portage Learning exam or a reproduction of leaked/proprietary exam content.
1. The concept of treating every known or unknown specimen as potentially hazardous is called:
Universal precautions
Selective culture
Differential staining
Aseptic isolation
2. Which observation is most directly a morphological characteristic of an unknown bacterium?
Catalase reaction
Cell size and shape
Gas production
Acid production
3. When the same limited liquid sample must be tested for motility and Gram status, which should be assessed first?
Motility
Gram status
Hemolysis
Catalase activity
4. Why should motility be assessed before performing a Gram stain on the same limited live sample?
Gram staining increases motility
Motility requires a dry smear
Motility can only be seen after decolorization
Gram staining includes fixation that kills the cells
5. A facultative anaerobe can grow:
Only without oxygen
Only in high carbon dioxide
Only with oxygen
With or without oxygen
6. Which observation would be appropriate when examining an unknown microbial culture?
Antibiotic prescription
Color change in the organism or surrounding medium
Patient blood type
Host age only
7. Which item is NOT a standard observation of an unknown microbial sample?
Gram reaction
Patient's favorite food
Cell size and shape
Motility
8. Why are unknown cultures handled with universal precautions?
They must always be sterile
All unknowns are definitely pathogens
Their pathogenic potential may not be known
They contain only viruses
BIOL 271 • Module 5 Exam Review • Original exam-style practice Page 1
, Unknown-sample assessment workflow
Live sample Motility Gram stain Biochemical tests R
Original schematic: assess a live unknown before destructive fixation when both motility and Gram status are required.
9. Which personal protective equipment is most appropriate as a routine barrier when handling unknown cultures?
Open-toed shoes only
No PPE if the sample is clear
Laboratory gloves and protective clothing as required
Jewelry
10. A wet mount is particularly useful for assessing:
Gram reaction
Acid-fastness
Motility
Capsule chemistry only
11. A heat-fixed smear is used in the Gram-staining process primarily to:
Create a capsule
Supply oxygen
Adhere and kill cells on the slide
Increase bacterial motility
12. Which result is a chemical observation rather than a morphological observation?
Cell arrangement
A positive catalase reaction
Rod shape
Coccus shape
13. Which finding should be documented when an unknown organism changes the color of the surrounding medium?
Nothing because color is irrelevant
The location and nature of the color change
Only the patient's symptoms
Only the microscope brand
14. A researcher should capture images or drawings of important findings because they:
Replace all laboratory controls
Eliminate the need for staining
Guarantee species identification
Provide a record of observed characteristics
15. Which pair contains two direct observations useful for preliminary microbial identification?
Medication dose and pulse
Patient height and weight
Shape and motility
Room number and date of birth
16. Streptococcus species are generally:
Catalase positive
Catalase negative
Acid-fast
Oxidase positive only
17. Because Streptococcus is catalase negative, exposure to accumulated peroxide can:
Promote unlimited growth
BIOL 271 • Module 5 Exam Review • Original exam-style practice Page 2
, Make them acid-fast
Convert the cells to Gram-negative
Damage the cells because they cannot efficiently break it down
18. A common non-selective but differential medium used to evaluate suspected Streptococcus is:
Sabouraud agar
Blood agar
MacConkey agar
Mannitol salt agar only
19. The clear zone around a colony on blood agar represents:
Beta hemolysis
Gamma hemolysis
Alpha hemolysis
No growth
20. Alpha hemolysis is characterized by:
Blackening of the agar
Partial hemolysis with a greenish discoloration
No change in the agar
Complete clearing around colonies
21. Gamma hemolysis means:
Complete hemolysis
Partial hemolysis
No detectable hemolysis
Gas production
22. Which hemolytic pattern is associated with complete destruction of red blood cells?
Beta
Delta
Alpha
Gamma
23. Streptococcus pyogenes belongs to:
Lancefield group C
Lancefield group D
Lancefield group B
Lancefield group A
24. Streptococcus agalactiae is classically associated with:
Lancefield group B
Lancefield group A
Lancefield group C
Lancefield group D
25. Lancefield grouping is based primarily on:
Flagellar length
Cell-wall carbohydrate antigens
Capsule thickness only
Colony diameter
26. The organism most classically associated with strep throat is:
Staphylococcus epidermidis
Streptococcus pyogenes
Neisseria gonorrhoeae
Clostridium botulinum
27. An important immune-mediated complication of untreated streptococcal pharyngitis is:
Botulism
Gonorrhea
Rheumatic fever
Tetanus
BIOL 271 • Module 5 Exam Review • Original exam-style practice Page 3
Browser | Portage Learning
250 original, exam-style practice questions built from publicly visible Module 5 topic coverage. Correct choices are marked inline with a green tick in a box.
This is not an official Portage Learning exam or a reproduction of leaked/proprietary exam content.
1. The concept of treating every known or unknown specimen as potentially hazardous is called:
Universal precautions
Selective culture
Differential staining
Aseptic isolation
2. Which observation is most directly a morphological characteristic of an unknown bacterium?
Catalase reaction
Cell size and shape
Gas production
Acid production
3. When the same limited liquid sample must be tested for motility and Gram status, which should be assessed first?
Motility
Gram status
Hemolysis
Catalase activity
4. Why should motility be assessed before performing a Gram stain on the same limited live sample?
Gram staining increases motility
Motility requires a dry smear
Motility can only be seen after decolorization
Gram staining includes fixation that kills the cells
5. A facultative anaerobe can grow:
Only without oxygen
Only in high carbon dioxide
Only with oxygen
With or without oxygen
6. Which observation would be appropriate when examining an unknown microbial culture?
Antibiotic prescription
Color change in the organism or surrounding medium
Patient blood type
Host age only
7. Which item is NOT a standard observation of an unknown microbial sample?
Gram reaction
Patient's favorite food
Cell size and shape
Motility
8. Why are unknown cultures handled with universal precautions?
They must always be sterile
All unknowns are definitely pathogens
Their pathogenic potential may not be known
They contain only viruses
BIOL 271 • Module 5 Exam Review • Original exam-style practice Page 1
, Unknown-sample assessment workflow
Live sample Motility Gram stain Biochemical tests R
Original schematic: assess a live unknown before destructive fixation when both motility and Gram status are required.
9. Which personal protective equipment is most appropriate as a routine barrier when handling unknown cultures?
Open-toed shoes only
No PPE if the sample is clear
Laboratory gloves and protective clothing as required
Jewelry
10. A wet mount is particularly useful for assessing:
Gram reaction
Acid-fastness
Motility
Capsule chemistry only
11. A heat-fixed smear is used in the Gram-staining process primarily to:
Create a capsule
Supply oxygen
Adhere and kill cells on the slide
Increase bacterial motility
12. Which result is a chemical observation rather than a morphological observation?
Cell arrangement
A positive catalase reaction
Rod shape
Coccus shape
13. Which finding should be documented when an unknown organism changes the color of the surrounding medium?
Nothing because color is irrelevant
The location and nature of the color change
Only the patient's symptoms
Only the microscope brand
14. A researcher should capture images or drawings of important findings because they:
Replace all laboratory controls
Eliminate the need for staining
Guarantee species identification
Provide a record of observed characteristics
15. Which pair contains two direct observations useful for preliminary microbial identification?
Medication dose and pulse
Patient height and weight
Shape and motility
Room number and date of birth
16. Streptococcus species are generally:
Catalase positive
Catalase negative
Acid-fast
Oxidase positive only
17. Because Streptococcus is catalase negative, exposure to accumulated peroxide can:
Promote unlimited growth
BIOL 271 • Module 5 Exam Review • Original exam-style practice Page 2
, Make them acid-fast
Convert the cells to Gram-negative
Damage the cells because they cannot efficiently break it down
18. A common non-selective but differential medium used to evaluate suspected Streptococcus is:
Sabouraud agar
Blood agar
MacConkey agar
Mannitol salt agar only
19. The clear zone around a colony on blood agar represents:
Beta hemolysis
Gamma hemolysis
Alpha hemolysis
No growth
20. Alpha hemolysis is characterized by:
Blackening of the agar
Partial hemolysis with a greenish discoloration
No change in the agar
Complete clearing around colonies
21. Gamma hemolysis means:
Complete hemolysis
Partial hemolysis
No detectable hemolysis
Gas production
22. Which hemolytic pattern is associated with complete destruction of red blood cells?
Beta
Delta
Alpha
Gamma
23. Streptococcus pyogenes belongs to:
Lancefield group C
Lancefield group D
Lancefield group B
Lancefield group A
24. Streptococcus agalactiae is classically associated with:
Lancefield group B
Lancefield group A
Lancefield group C
Lancefield group D
25. Lancefield grouping is based primarily on:
Flagellar length
Cell-wall carbohydrate antigens
Capsule thickness only
Colony diameter
26. The organism most classically associated with strep throat is:
Staphylococcus epidermidis
Streptococcus pyogenes
Neisseria gonorrhoeae
Clostridium botulinum
27. An important immune-mediated complication of untreated streptococcal pharyngitis is:
Botulism
Gonorrhea
Rheumatic fever
Tetanus
BIOL 271 • Module 5 Exam Review • Original exam-style practice Page 3
