Question 1

This microscope produces an image of a light cell against a dark background; internal structures are NOT visible.

Accepted Answer

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

Question 2

The negative stain is used to

Accepted Answer

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

Question 3

Which microscope can be used to visualize DNA or botulinum toxin?

Accepted Answer

A)  scanning tunneling microscope 
B)  scanning electron microscope 
C)  compound light microscope 
D)  confocal microscope 
E)  phase- contrast microscope 
A)  scanning tunneling microscope 
B)  scanning electron microscope 
C)  compound light microscope 
D)  confocal microscope 
E)  phase- contrast microscope A

Question 4

Which microscope takes advantage of differences in the refractive indexes of cell structures?

Accepted Answer

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

Question 5

Simple staining is often necessary to improve contrast in which microscope?

Accepted Answer

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

Question 6

Which of the following is NOT useful for observing living cells?

Accepted Answer

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

Question 7

If acid- fast bacteria are stained with the Gram stain, they will stain gram- negative.

Accepted Answer

A) True 
 B)False

Question 8

The counterstain used in the Gram stain is a basic dye.

Accepted Answer

A) True 
 B)False

Question 9

The purpose of a mordant in the Gram stain is to

Accepted Answer

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

Question 10

You are studying a cell structure that is approximately 100 nm in size. Which of the following provides the lowest magnification you can use to see this structure?

Accepted Answer

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

Question 11

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

Accepted Answer

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

Question 12

Which of the following places the steps of the Gram stain in the correct order? 1- Alcohol- acetone 2- Crystal violet
3- Safranin
4- Iodine

Accepted Answer

A)  2- 1- 4- 3 
B)  1- 2- 3- 4 
C)  2- 4- 1- 3 
D)  1- 3- 2- 4 
E)  4- 3- 2- 1 
A)  2- 1- 4- 3 
B)  1- 2- 3- 4 
C)  2- 4- 1- 3 
D)  1- 3- 2- 4 
E)  4- 3- 2- 1

Question 13

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

Accepted Answer

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

Question 14

In a completed Gram stain, gram- negative bacteria are colorless.

Accepted Answer

A) True 
 B)False

Question 15

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

Accepted Answer

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

Question 16

) In microscopy, the term resolution

Accepted Answer

A)  is improved when longer wavelengths of light are employed. 
B)  refers to the ability to distinguish fine structure and detail in a specimen. 
C)  refers to magnification when using the electron microscope. 
D)  is the same as the total magnification of a specimen. 
E)  is only observed in stained specimens. 
A)  is improved when longer wavelengths of light are employed. 
B)  refers to the ability to distinguish fine structure and detail in a specimen. 
C)  refers to magnification when using the electron microscope. 
D)  is the same as the total magnification of a specimen. 
E)  is only observed in stained specimens.

Question 17

The resolution of a microscope can be improved by changing the

Accepted Answer

A)  wavelength of light. 
B)  condenser. 
C)  coarse adjustment. 
D)  diaphragm. 
E)  fine adjustment. 
A)  wavelength of light. 
B)  condenser. 
C)  coarse adjustment. 
D)  diaphragm. 
E)  fine adjustment.

Question 18

You are performing a Gram stain on gram- positive bacteria and you stop after the addition of the counterstain. What is the appearance of the bacteria at this point?

Accepted Answer

A)  colorless 
B)  brown 
C)  purple 
D)  red 
A)  colorless 
B)  brown 
C)  purple 
D)  red

Question 19

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

Question 20

Which of the following is NOT equal to 1 mm?

Accepted Answer

A)  10 6 nm 
B)  100 µm 
C)  0.1 cm 
D)  10- 3 m 
E)  0.001 m 
A)  10 6 nm 
B)  100 µm 
C)  0.1 cm 
D)  10- 3 m 
E)  0.001 m

Exam 3: Observing Microorganisms Through a Microscope

This microscope produces an image of a light cell against a dark background; internal structures are NOT visible.

The negative stain is used to

Which microscope can be used to visualize DNA or botulinum toxin?

Which microscope takes advantage of differences in the refractive indexes of cell structures?

Simple staining is often necessary to improve contrast in which microscope?

Which of the following is NOT useful for observing living cells?

If acid- fast bacteria are stained with the Gram stain, they will stain gram- negative.

The counterstain used in the Gram stain is a basic dye.

The purpose of a mordant in the Gram stain is to

You are studying a cell structure that is approximately 100 nm in size. Which of the following provides the lowest magnification you can use to see this structure?

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

Which of the following places the steps of the Gram stain in the correct order? 1- Alcohol- acetone 2- Crystal violet 3- Safranin 4- Iodine

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

In a completed Gram stain, gram- negative bacteria are colorless.

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

) In microscopy, the term resolution

The resolution of a microscope can be improved by changing the

You are performing a Gram stain on gram- positive bacteria and you stop after the addition of the counterstain. What is the appearance of the bacteria at this point?

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 is NOT equal to 1 mm?

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 Recombinant Dna

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 Diseases of the Urinary and Reproductive Systems

Environmental Microbiology

Applied and Industrial Microbiology

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