1
Test Bank for Nester's
Microbiology: A Human
Perspective, 10th Edition
.approved edition(q&a) +
rationales
Section 1: The Microbial World (Chapters 1–3
1. Which of the following is NOT a characteristic of all living organisms?
a) Metabolism
b) Motility
c) Reproduction
d) Adaptation
Aanswer: b
Rationale: Motility (ability to move independently) is not universal; many microbes are non-motile.
Metabolism, reproduction, and adaptation are fundamental properties of life.
2. The term used to describe the use of microorganisms to clean up environmental pollutants is:
a) Biotechnology
b) Bioremediation
c) Biological control
d) Sanitization
Aanswer: b
Rationale: Bioremediation specifically uses microbes to degrade or remove pollutants like oil or heavy
metals.
3. Which scientist first observed bacteria using a simple microscope?
a) Robert Hooke
b) Louis Pasteur
c) Antonie van Leeuwenhoek
d) Rudolf Virchow
Aanswer: c
Rationale: Van Leeuwenhoek ground lenses and observed “animalcules” (bacteria and protozoa) in the
1670s.
,2
4. A prokaryotic cell is characterized by:
a) A membrane-bound nucleus
b) Membrane-bound organelles
c) Lack of a nucleus and membrane-bound organelles
d) Presence of a cell wall made of cellulose
Aanswer: c
Rationale: Prokaryotes (bacteria and archaea) have no nucleus or membrane-bound organelles. Their
cell wall is usually peptidoglycan (bacteria).
5. Which of the following is an example of a microbial mutualism?
a) Salmonella infecting the human gut
b) Rhizobium bacteria in legume root nodules
c) A virus replicating inside a host cell
d) A fungus producing antibiotics
Aanswer: b
Rationale: Mutualism benefits both partners. Rhizobium fixes nitrogen for the plant and receives
nutrients.
Section 2: Microscopy and Staining (Chapter 4)
6. The resolving power of a microscope is defined as:
a) The ability to enlarge an image
b) The ability to distinguish two adjacent objects as separate
c) The clarity of the background
d) The intensity of the light source
Aanswer: b
Rationale: Resolution is the minimum distance at which two points can be seen as distinct.
Magnification alone is not enough.
7. In the Gram stain, bacteria that appear purple are:
a) Gram-negative
b) Gram-positive
c) Acid-fast
d) Endospore-formers
Aanswer: b
Rationale: Gram-positive cells retain crystal violet-iodine complex due to thick peptidoglycan layer.
8. Which type of microscopy uses a laser to scan the specimen and create a 3D image?
a) Transmission electron microscopy
b) Scanning electron microscopy
c) Confocal laser scanning microscopy
d) Darkfield microscopy
Aanswer: c
*Rationale: Confocal microscopy uses pinholes and lasers to eliminate out-of-focus light, enabling
optical sectioning and 3D reconstruction.*
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9. An acid-fast stain is used to identify:
a) Bacillus anthracis
b) Streptococcus pyogenes
c) Mycobacterium tuberculosis
d) Escherichia coli
Aanswer: c
Rationale: Acid-fast bacteria have mycolic acid in their cell walls, resisting decolorization by acid-
alcohol.
10. The total magnification of a compound light microscope with a 10x eyepiece and a 40x objective lens
is:
a) 40x
b) 400x
c) 1000x
d) 4000x
Aanswer: b
*Rationale: Total magnification = ocular × objective = 10 × 40 = 400x.*
Section 3: Prokaryotic and Eukaryotic Cell Structure (Chapters 5–6)
11. Which structure is found in both Gram-positive and Gram-negative bacteria?
a) Outer membrane
b) Peptidoglycan
c) Teichoic acid
d) Lipopolysaccharide
Aanswer: b
Rationale: All bacteria have peptidoglycan (except Mycoplasma). Teichoic acid is only in Gram-positive;
outer membrane and LPS are only in Gram-negative.
12. The function of bacterial endospores is:
a) Reproduction
b) Survival under harsh conditions
c) Attachment to surfaces
d) Genetic exchange
Aanswer: b
Rationale: Endospores are metabolically dormant, highly resistant structures for survival, not
reproduction.
13. Which eukaryotic organelle contains its own DNA and is involved in energy production?
a) Nucleus
b) Ribosome
c) Mitochondrion
d) Golgi apparatus
Aanswer: c
Rationale: Mitochondria have their own circular DNA and produce ATP via oxidative phosphorylation.
Test Bank for Nester's
Microbiology: A Human
Perspective, 10th Edition
.approved edition(q&a) +
rationales
Section 1: The Microbial World (Chapters 1–3
1. Which of the following is NOT a characteristic of all living organisms?
a) Metabolism
b) Motility
c) Reproduction
d) Adaptation
Aanswer: b
Rationale: Motility (ability to move independently) is not universal; many microbes are non-motile.
Metabolism, reproduction, and adaptation are fundamental properties of life.
2. The term used to describe the use of microorganisms to clean up environmental pollutants is:
a) Biotechnology
b) Bioremediation
c) Biological control
d) Sanitization
Aanswer: b
Rationale: Bioremediation specifically uses microbes to degrade or remove pollutants like oil or heavy
metals.
3. Which scientist first observed bacteria using a simple microscope?
a) Robert Hooke
b) Louis Pasteur
c) Antonie van Leeuwenhoek
d) Rudolf Virchow
Aanswer: c
Rationale: Van Leeuwenhoek ground lenses and observed “animalcules” (bacteria and protozoa) in the
1670s.
,2
4. A prokaryotic cell is characterized by:
a) A membrane-bound nucleus
b) Membrane-bound organelles
c) Lack of a nucleus and membrane-bound organelles
d) Presence of a cell wall made of cellulose
Aanswer: c
Rationale: Prokaryotes (bacteria and archaea) have no nucleus or membrane-bound organelles. Their
cell wall is usually peptidoglycan (bacteria).
5. Which of the following is an example of a microbial mutualism?
a) Salmonella infecting the human gut
b) Rhizobium bacteria in legume root nodules
c) A virus replicating inside a host cell
d) A fungus producing antibiotics
Aanswer: b
Rationale: Mutualism benefits both partners. Rhizobium fixes nitrogen for the plant and receives
nutrients.
Section 2: Microscopy and Staining (Chapter 4)
6. The resolving power of a microscope is defined as:
a) The ability to enlarge an image
b) The ability to distinguish two adjacent objects as separate
c) The clarity of the background
d) The intensity of the light source
Aanswer: b
Rationale: Resolution is the minimum distance at which two points can be seen as distinct.
Magnification alone is not enough.
7. In the Gram stain, bacteria that appear purple are:
a) Gram-negative
b) Gram-positive
c) Acid-fast
d) Endospore-formers
Aanswer: b
Rationale: Gram-positive cells retain crystal violet-iodine complex due to thick peptidoglycan layer.
8. Which type of microscopy uses a laser to scan the specimen and create a 3D image?
a) Transmission electron microscopy
b) Scanning electron microscopy
c) Confocal laser scanning microscopy
d) Darkfield microscopy
Aanswer: c
*Rationale: Confocal microscopy uses pinholes and lasers to eliminate out-of-focus light, enabling
optical sectioning and 3D reconstruction.*
, 3
9. An acid-fast stain is used to identify:
a) Bacillus anthracis
b) Streptococcus pyogenes
c) Mycobacterium tuberculosis
d) Escherichia coli
Aanswer: c
Rationale: Acid-fast bacteria have mycolic acid in their cell walls, resisting decolorization by acid-
alcohol.
10. The total magnification of a compound light microscope with a 10x eyepiece and a 40x objective lens
is:
a) 40x
b) 400x
c) 1000x
d) 4000x
Aanswer: b
*Rationale: Total magnification = ocular × objective = 10 × 40 = 400x.*
Section 3: Prokaryotic and Eukaryotic Cell Structure (Chapters 5–6)
11. Which structure is found in both Gram-positive and Gram-negative bacteria?
a) Outer membrane
b) Peptidoglycan
c) Teichoic acid
d) Lipopolysaccharide
Aanswer: b
Rationale: All bacteria have peptidoglycan (except Mycoplasma). Teichoic acid is only in Gram-positive;
outer membrane and LPS are only in Gram-negative.
12. The function of bacterial endospores is:
a) Reproduction
b) Survival under harsh conditions
c) Attachment to surfaces
d) Genetic exchange
Aanswer: b
Rationale: Endospores are metabolically dormant, highly resistant structures for survival, not
reproduction.
13. Which eukaryotic organelle contains its own DNA and is involved in energy production?
a) Nucleus
b) Ribosome
c) Mitochondrion
d) Golgi apparatus
Aanswer: c
Rationale: Mitochondria have their own circular DNA and produce ATP via oxidative phosphorylation.
