Question 1

Which type of stain is most useful in helping clinicians to decide which antibiotic to prescribe for a bacterial infection?

Accepted Answer

A)  negative stain 
B)  Gram stain 
C)  endospore stain 
D)  simple stain 
E)  flagella stain 
A)  negative stain 
B)  Gram stain 
C)  endospore stain 
D)  simple stain 
E)  flagella stain

Question 2

In 1877, Robert Koch thought preparing permanently stained slides would be valuable. Why was his assessment correct?

Accepted Answer

In 1877, Robert Koch, a pioneering micro

Question 3

Which of the following correctly traces the path of light through the compound microscope?

Accepted Answer

A)  light source; specimen; condenser; objective lens; ocular lens 
B)  light source; condenser; specimen; objective lens; ocular lens 
C)  light source; condenser; objective lens; specimen; ocular lens 
D)  condenser; light source; specimen; ocular lens; objective lens 
E)  condenser; light source; specimen; objective lens; ocular lens 
A)  light source; specimen; condenser; objective lens; ocular lens 
B)  light source; condenser; specimen; objective lens; ocular lens 
C)  light source; condenser; objective lens; specimen; ocular lens 
D)  condenser; light source; specimen; ocular lens; objective lens 
E)  condenser; light source; specimen; objective lens; ocular lens

Question 4

Which microscope is most useful for visualizing a biofilm?

Accepted Answer

A)  phase-contrast microscope 
B)  scanning acoustic microscope 
C)  transmission electron microscope 
D)  fluorescence microscope 
E)  compound light microscope 
A)  phase-contrast microscope 
B)  scanning acoustic microscope 
C)  transmission electron microscope 
D)  fluorescence microscope 
E)  compound light microscope

Question 5

A virus measures 100 nm in length. What is its length in μm?

Accepted Answer

A)  0.1 μm 
B)  1 μm 
C)  0.001 μm 
D)  10 μm 
E)  0.01 μm 
A)  0.1 μm 
B)  1 μm 
C)  0.001 μm 
D)  10 μm 
E)  0.01 μm

Question 6

Which microscope is best used for observing the surfaces of intact cells and viruses?

Accepted Answer

A)  darkfield microscope 
B)  phase-contrast microscope 
C)  scanning electron microscope 
D)  brightfield microscope 
E)  fluorescence microscope 
A)  darkfield microscope 
B)  phase-contrast microscope 
C)  scanning electron microscope 
D)  brightfield microscope 
E)  fluorescence microscope

Question 7

Which microscope is used to observe a specimen that emits light when illuminated with an ultraviolet light?

Accepted Answer

A)  darkfield microscope 
B)  electron microscope 
C)  phase-contrast microscope 
D)  compound light microscope 
E)  fluorescence microscope 
A)  darkfield microscope 
B)  electron microscope 
C)  phase-contrast microscope 
D)  compound light microscope 
E)  fluorescence microscope

Question 8

Both phase-contrast microscopy and differential interference contrast microscopy are used to view the internal structures of cells without staining.

Accepted Answer

A) True 
 B)False

Question 9

The negative stain is used to

Accepted Answer

A)  determine cell size. 
B)  determine Gram reaction. 
C)  visualize endospores. 
D)  determine flagella arrangement. 
E)  visualize capsules. 
A)  determine cell size. 
B)  determine Gram reaction. 
C)  visualize endospores. 
D)  determine flagella arrangement. 
E)  visualize capsules.

Question 10

Which step in the Gram stain is the critical step in differentiating gram-positive cells from gram-negative cells?

Accepted Answer

A)  crystal violet 
B)  safranin 
C)  alcohol-acetone 
D)  iodine 
A)  crystal violet 
B)  safranin 
C)  alcohol-acetone 
D)  iodine

Question 11

Which microscope is used to see internal structures of cells in a natural state?

Accepted Answer

A)  fluorescence microscope 
B)  phase-contrast microscope 
C)  compound light microscope 
D)  electron microscope 
E)  darkfield microscope 
A)  fluorescence microscope 
B)  phase-contrast microscope 
C)  compound light microscope 
D)  electron microscope 
E)  darkfield microscope

Question 12

Assume you stain Bacillus by applying malachite green with heat and then counterstaining with safranin. Through the microscope, the green structures are

Accepted Answer

A)  capsules. 
B)  flagella. 
C)  endospores. 
D)  cell walls. 
E)  The answer cannot be determined. 
A)  capsules. 
B)  flagella. 
C)  endospores. 
D)  cell walls. 
E)  The answer cannot be determined.

Question 13

Which of the following pairs is mismatched?

Accepted Answer

A)  methylene blue ‐ simple stain 
B)  crystal violet ‐ simple stain 
C)  nigrosin ‐ negative stain 
D)  basic dye ‐ negative stain 
E)  acidic dye ‐ capsule stain 
A)  methylene blue ‐ simple stain 
B)  crystal violet ‐ simple stain 
C)  nigrosin ‐ negative stain 
D)  basic dye ‐ negative stain 
E)  acidic dye ‐ capsule stain

Question 14

Figure 3.1   In Figure 3.1, line ʺcʺ points to the microscopeʹs

Accepted Answer

A)  illuminator. 
B)  ocular lens. 
C)  objective lens. 
D)  condenser. 
A)  illuminator. 
B)  ocular lens. 
C)  objective lens. 
D)  condenser.

Question 15

Which microscope is used to see detail of a 300 -nm virus?

Accepted Answer

A)  darkfield microscope 
B)  DIC microscope 
C)  fluorescence microscope 
D)  phase-contrast microscope 
E)  electron microscope 
A)  darkfield microscope 
B)  DIC microscope 
C)  fluorescence microscope 
D)  phase-contrast microscope 
E)  electron microscope

Question 16

The purpose of a mordant in the Gram stain is to

Accepted Answer

A)  make the bacterial cells larger. 
B)  make the flagella visible. 
C)  remove the simple stain. 
D)  prevent the crystal violet from leaving the cells. 
E)  make gram-negative cells visible. 
A)  make the bacterial cells larger. 
B)  make the flagella visible. 
C)  remove the simple stain. 
D)  prevent the crystal violet from leaving the cells. 
E)  make gram-negative cells visible.

Question 17

Cells viewed in darkfield microscopy appear similar to those stained with the negative stain.

Accepted Answer

A) True 
 B)False

Question 18

Which of the following pairs is mismatched?

Accepted Answer

A)  confocal microscope ‐ produces a three-dimensional image 
B)  scanning electron microscope ‐ produces a three-dimensional image 
C)  fluorescence microscope ‐ uses a fluorescent light 
D)  darkfield microscope ‐ uses visible light 
E)  scanning tunneling microscope ‐ allows visualization of atoms 
A)  confocal microscope ‐ produces a three-dimensional image 
B)  scanning electron microscope ‐ produces a three-dimensional image 
C)  fluorescence microscope ‐ uses a fluorescent light 
D)  darkfield microscope ‐ uses visible light 
E)  scanning tunneling microscope ‐ allows visualization of atoms

Exam 3: Observing Microorganisms Through a Microscope

Which type of stain is most useful in helping clinicians to decide which antibiotic to prescribe for a bacterial infection?

In 1877, Robert Koch thought preparing permanently stained slides would be valuable. Why was his assessment correct?

Which of the following correctly traces the path of light through the compound microscope?

Which microscope is most useful for visualizing a biofilm?

A virus measures 100 nm in length. What is its length in μm?

Which microscope is best used for observing the surfaces of intact cells and viruses?

Which microscope is used to observe a specimen that emits light when illuminated with an ultraviolet light?

Both phase-contrast microscopy and differential interference contrast microscopy are used to view the internal structures of cells without staining.

The negative stain is used to

Which step in the Gram stain is the critical step in differentiating gram-positive cells from gram-negative cells?

Which microscope is used to see internal structures of cells in a natural state?

Assume you stain Bacillus by applying malachite green with heat and then counterstaining with safranin. Through the microscope, the green structures are

Which of the following pairs is mismatched?

Figure 3.1 In Figure 3.1, line ʺcʺ points to the microscopeʹs

Which microscope is used to see detail of a 300 -nm virus?

The purpose of a mordant in the Gram stain is to

Cells viewed in darkfield microscopy appear similar to those stained with the negative stain.

Which of the following pairs is mismatched?

The Microbial World and You

Chemical Principles

Functional Anatomy of Prokaryotic and Eukaryotic Cells

Microbial Metabolism

Microbial Growth

The Control of Microbial Growth

Microbial Genetics

Biotechnology and Dna Technology

Classification of Microorganisms

The Prokaryotes: Domains Bacteria and Archaea

The Eukaryotes: Fungi, Algae, Protozoa, and Helminths

Viruses, Viroids, and Prions

Principles of Disease and Epidemiology

Microbial Mechanisms of Pathogenicity

Innate Immunity: Nonspecific Defenses of the Host

Adaptive Immunity: Specific Defenses of the Host

Practical Applications of Immunology

Disorders Associated With the Immune System

Antimicrobial Drugs

Microbial Diseases of the Skin and Eyes

Microbial Diseases of the Nervous System

Microbial Diseases of the Cardiovascular and Lymphatic Systems

Microbial Diseases of the Respiratory System

Microbial Diseases of the Digestive System

Microbial Disease of the Urinary and Reproductive Systems

Environmental Microbiology

Applied and Industrial Microbiology

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