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Chamberlain University-Illinois
NR 222
Microbiology Exam 2 Questions and
Answers 2026 Latest Update
What is an organism that grows in lower pH conditions called?
Neutrophile
Alkalinophile
Halophile
Barophile
Acidophile Ans: Acidophile
Which term describes a microorganism that obtains nutrients by
decomposing dead organic matter in its environment?
Saprobe
Predator
Parasite
Autotroph
Commensal Ans: Saprobe
Organisms that use inorganic carbon sources (such as carbon dioxide) are
known as___________________.
Organisms that use organic carbon sources (such as glucose) are known as
_________________________. Ans: autotrophs, heterotrophs
You have discovered a new microorganism while studying out in the field.
After running some tests, you conclude that the organism uses inorganic
© 2026 All rights reserved
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carbon from carbon dioxide and acquires energy from light. Which category
does this microorganism fall under?
Chemoautotroph
Chemoheterotroph
Photoautotroph
Photoheterotroph Ans: Photoautotroph
In what environment would a halophile live?
Hypotonic
Fresh water
Hypertonic
Isotonic Ans: Hypertonic
What is the term for microorganisms that can withstand brief exposure to
elevated temperatures?
Thermophiles
Psychrotolerant
Psychrophiles
Thermoduric
Mesophiles Ans: Thermoduric
Which growth phase requires cells to go through a period of adjustment,
enlargement, and synthesis?
Death phase
Stationary phase
Exponential growth phase
Lag phase Ans: Lag phase
© 2026 All rights reserved
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What type of microorganism obtains energy and carbon by breaking down
organic molecules?
Saprobe
Autotroph
Phototroph
Chemoheterotroph
Chemolithotroph Ans: Chemoheterotroph
During which phase of microbial growth do microorganisms experience
rapid and continuous cell division, doubling the population with each
generation?
Exponential growth phase
Lag phase
Stationary phase
Death phase Ans: Exponential growth phase
In a thioglycolate tube, where would you expect to find microorganisms that
only grow in the absence of oxygen, such as Clostridium species?
Near the surface, where oxygen is abundant
At the bottom of the tube, where oxygen is completely depleted
In the middle of the tube, where oxygen concentration is lower
Throughout the entire length of the tube, without a preference for oxygen
levels
Near the side of the tube, forming a biofilm to protect against oxygen
exposure Ans: At the bottom of the tube, where oxygen is completely
depleted
What is the main difference between a saprobe and a parasite?
A saprobe cannot infect a human, but a parasite is always infectious.
© 2026 All rights reserved
Chamberlain University-Illinois
NR 222
Microbiology Exam 2 Questions and
Answers 2026 Latest Update
What is an organism that grows in lower pH conditions called?
Neutrophile
Alkalinophile
Halophile
Barophile
Acidophile Ans: Acidophile
Which term describes a microorganism that obtains nutrients by
decomposing dead organic matter in its environment?
Saprobe
Predator
Parasite
Autotroph
Commensal Ans: Saprobe
Organisms that use inorganic carbon sources (such as carbon dioxide) are
known as___________________.
Organisms that use organic carbon sources (such as glucose) are known as
_________________________. Ans: autotrophs, heterotrophs
You have discovered a new microorganism while studying out in the field.
After running some tests, you conclude that the organism uses inorganic
© 2026 All rights reserved
, 2 | Page
carbon from carbon dioxide and acquires energy from light. Which category
does this microorganism fall under?
Chemoautotroph
Chemoheterotroph
Photoautotroph
Photoheterotroph Ans: Photoautotroph
In what environment would a halophile live?
Hypotonic
Fresh water
Hypertonic
Isotonic Ans: Hypertonic
What is the term for microorganisms that can withstand brief exposure to
elevated temperatures?
Thermophiles
Psychrotolerant
Psychrophiles
Thermoduric
Mesophiles Ans: Thermoduric
Which growth phase requires cells to go through a period of adjustment,
enlargement, and synthesis?
Death phase
Stationary phase
Exponential growth phase
Lag phase Ans: Lag phase
© 2026 All rights reserved
, 3 | Page
What type of microorganism obtains energy and carbon by breaking down
organic molecules?
Saprobe
Autotroph
Phototroph
Chemoheterotroph
Chemolithotroph Ans: Chemoheterotroph
During which phase of microbial growth do microorganisms experience
rapid and continuous cell division, doubling the population with each
generation?
Exponential growth phase
Lag phase
Stationary phase
Death phase Ans: Exponential growth phase
In a thioglycolate tube, where would you expect to find microorganisms that
only grow in the absence of oxygen, such as Clostridium species?
Near the surface, where oxygen is abundant
At the bottom of the tube, where oxygen is completely depleted
In the middle of the tube, where oxygen concentration is lower
Throughout the entire length of the tube, without a preference for oxygen
levels
Near the side of the tube, forming a biofilm to protect against oxygen
exposure Ans: At the bottom of the tube, where oxygen is completely
depleted
What is the main difference between a saprobe and a parasite?
A saprobe cannot infect a human, but a parasite is always infectious.
© 2026 All rights reserved
