,BIOD 171 Module 5 | Practice Q&A | 2026/2027 | Microbiology |
Portage Learning
1. The concept of treating all samples, whether known or unknown, as
potentially hazardous or pathogenic materials is known as what?
A) Standard precautions
B) Universal precautions
C) Contact precautions
D) Droplet precautions
Correct Answer: Universal precautions
Rationale: Universal precautions means any and all samples, whether known
or unknown, are to be treated as potentially hazardous or pathogenic
materials. This infection control approach treats all human blood and body
fluids as infectious.
2. Which of the following would a researcher be certain to note while
analyzing an unknown microbial sample? (Select all that apply)
A) Size and shape
B) Any observable motility
C) Gram status
D) All of the above
Correct Answer: All of the above
Rationale: A researcher would note size and shape, any observable motility,
Gram status, the presence of chemical reactions, changes in color, and
capture images of characteristics.
,3. While observing an unknown sample of limited amount, a researcher must
determine both motility and Gram status using the same sample. Which
should be determined first and why?
A) Gram stain first, then motility, because Gram stain differentiates cell wall
type
B) Motility first, then Gram stain, because heat fixation in Gram stain kills
motile organisms
C) Either order works; results do not interfere
D) Neither test can be performed with limited sample
Correct Answer: Motility first, then Gram stain, because heat fixation in Gram
stain kills motile organisms
Rationale: Motility must be assessed first because heat fixation during Gram
staining kills motile organisms. Once heat-fixed, motility cannot be observed.
4. A facultative anaerobe is a microorganism capable of growth under what
conditions?
A) Only in the absence of oxygen (anaerobic conditions)
B) Only in the presence of oxygen (aerobic conditions)
C) Both aerobic and anaerobic conditions
D) Neither aerobic nor anaerobic conditions
Correct Answer: Both aerobic and anaerobic conditions
Rationale: A facultative anaerobe is capable of growth under both aerobic
and anaerobic conditions, adapting metabolically to survive with or without
oxygen.
, 5. Which non-selective yet differential agar plate should be used if a
Streptococcus sample is suspected?
A) MacConkey agar
B) Blood agar plate (BAP)
C) Mannitol Salt Agar (MSA)
D) EMB agar
Correct Answer: Blood agar plate (BAP)
Rationale: A blood agar plate (BAP) would be the quickest way to identify and
classify a potential Streptococcus microbe based on its hemolytic properties.
6. What disease can result if a patient with streptococcal pharyngitis goes
untreated?
A) Tuberculosis
B) Botulism
C) Rheumatic fever
D) Leprosy
Correct Answer: Rheumatic fever
Rationale: Rheumatic fever occurs in approximately 3% of untreated cases of
streptococcal pharyngitis, presenting approximately 2-3 weeks post-
infection.
7. Streptococcus, E. coli, Pseudomonas, and Klebsiella are all capable of
causing what disease?
A) Tuberculosis
B) Septicemia (blood poisoning)
Portage Learning
1. The concept of treating all samples, whether known or unknown, as
potentially hazardous or pathogenic materials is known as what?
A) Standard precautions
B) Universal precautions
C) Contact precautions
D) Droplet precautions
Correct Answer: Universal precautions
Rationale: Universal precautions means any and all samples, whether known
or unknown, are to be treated as potentially hazardous or pathogenic
materials. This infection control approach treats all human blood and body
fluids as infectious.
2. Which of the following would a researcher be certain to note while
analyzing an unknown microbial sample? (Select all that apply)
A) Size and shape
B) Any observable motility
C) Gram status
D) All of the above
Correct Answer: All of the above
Rationale: A researcher would note size and shape, any observable motility,
Gram status, the presence of chemical reactions, changes in color, and
capture images of characteristics.
,3. While observing an unknown sample of limited amount, a researcher must
determine both motility and Gram status using the same sample. Which
should be determined first and why?
A) Gram stain first, then motility, because Gram stain differentiates cell wall
type
B) Motility first, then Gram stain, because heat fixation in Gram stain kills
motile organisms
C) Either order works; results do not interfere
D) Neither test can be performed with limited sample
Correct Answer: Motility first, then Gram stain, because heat fixation in Gram
stain kills motile organisms
Rationale: Motility must be assessed first because heat fixation during Gram
staining kills motile organisms. Once heat-fixed, motility cannot be observed.
4. A facultative anaerobe is a microorganism capable of growth under what
conditions?
A) Only in the absence of oxygen (anaerobic conditions)
B) Only in the presence of oxygen (aerobic conditions)
C) Both aerobic and anaerobic conditions
D) Neither aerobic nor anaerobic conditions
Correct Answer: Both aerobic and anaerobic conditions
Rationale: A facultative anaerobe is capable of growth under both aerobic
and anaerobic conditions, adapting metabolically to survive with or without
oxygen.
, 5. Which non-selective yet differential agar plate should be used if a
Streptococcus sample is suspected?
A) MacConkey agar
B) Blood agar plate (BAP)
C) Mannitol Salt Agar (MSA)
D) EMB agar
Correct Answer: Blood agar plate (BAP)
Rationale: A blood agar plate (BAP) would be the quickest way to identify and
classify a potential Streptococcus microbe based on its hemolytic properties.
6. What disease can result if a patient with streptococcal pharyngitis goes
untreated?
A) Tuberculosis
B) Botulism
C) Rheumatic fever
D) Leprosy
Correct Answer: Rheumatic fever
Rationale: Rheumatic fever occurs in approximately 3% of untreated cases of
streptococcal pharyngitis, presenting approximately 2-3 weeks post-
infection.
7. Streptococcus, E. coli, Pseudomonas, and Klebsiella are all capable of
causing what disease?
A) Tuberculosis
B) Septicemia (blood poisoning)
