Question 1

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

Accepted Answer

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

Question 2

The purpose of a mordant in the Gram stain is to

Accepted Answer

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

Question 3

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

Accepted Answer

A) True 
 B)False

Question 4

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

Accepted Answer

A) True 
 B)False

Question 5

In 1884,Hans Christian Gram described a method of staining bacterial cells while not staining surrounding animal tissues.However,he thought that the staining method he developed was faulty because not all bacteria stained.In a letter to the editor of the journal in which Gram published his findings,write your response to Gram's concern.

Accepted Answer

Dear Hans Christian Gram,

I recently re

Question 6

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

Accepted Answer

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

Question 7

The negative stain is used to

Accepted Answer

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

Question 8

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

Question 9

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

Accepted Answer

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

Question 10

Which microscope is used to observe viruses and the internal structure of thinly sectioned cells?

Accepted Answer

A) transmission electron microscope 
B) darkfield microscope 
C) fluorescence microscope 
D) brightfield microscope 
E) scanning electron microscope 
A) transmission electron microscope 
B) darkfield microscope 
C) fluorescence microscope 
D) brightfield microscope 
E) scanning electron microscope

Question 11

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

Accepted Answer

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

Question 12

The resolution of a microscope can be improved by changing the

Accepted Answer

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

Question 13

In a completed Gram stain,gram-positive bacteria are purple.

Accepted Answer

A) True 
 B)False

Question 14

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

Accepted Answer

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

Question 15

Compare and contrast the Gram stain and the acid-fast stain.

Accepted Answer

The Gram stain and the acid-fast stain a

Question 16

Which microscope is most useful for visualizing a biofilm?

Accepted Answer

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

Question 17

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

Question 18

You are working in a clinical laboratory and you need to examine an unstained urine sample for the presence of bacteria.What type of light microscope should you use to observe this specimen? Explain your answer.

Accepted Answer

To examine an unstained urine sample for

Question 19

The capsules and flagella of bacteria can be observed in gram-stained smears.

Accepted Answer

A) True 
 B)False

Question 20

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

Accepted Answer

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

Exam 3: Observing Microorganisms Through a Microscope

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

The purpose of a mordant in the Gram stain is to

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

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

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

The negative stain is used to

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

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

Which microscope is used to observe viruses and the internal structure of thinly sectioned cells?

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

The resolution of a microscope can be improved by changing the

In a completed Gram stain,gram-positive bacteria are purple.

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

Compare and contrast the Gram stain and the acid-fast stain.

Which microscope is most useful for visualizing a biofilm?

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

You are working in a clinical laboratory and you need to examine an unstained urine sample for the presence of bacteria.What type of light microscope should you use to observe this specimen? Explain your answer.

The capsules and flagella of bacteria can be observed in gram-stained smears.

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

The Microbial World and You

Chemical Principles

Functional Anatomy of Prokaryotic and Eukaryotic

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 Diseases of the Urinary and Reproductive Systems

Environmental Microbiology

Applied and Industrial Microbiology

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