Question 1

Scattering of peripheral light rays through the glass slide under very high magnification can be prevented by ______.

Accepted Answer

A)   the condenser
B)   the ocular
C)   immersion oil
D)   the cover slipE) B) and D)
F) C) and D)

Question 2

Thioglycolate medium contains the following: yeast extract,pancreatic digest of casein,glucose,L-cysteine,sodium chloride,sodium thioglycolate,and agar.It is considered a complex medium because

Accepted Answer

A)   depending on their oxygen utilization pattern, organisms will grow differently on it.
B)   it has multiple ingredients for a broad range of nutrients.
C)   both yeast extract and pancreatic digest of casein are not chemically defined.
D)   thioglycolate has a carbon-sulfur bond that many microbes cannot break enzymatically.E) None of the above
F) A) and B)

Question 3

The type of microscopy in which you would observe brightly illuminated specimens against a black background is ______.

Accepted Answer

A)   dark-field
B)   confocal
C)   fluorescence
D)   phase-contrast
E)   electronF) A) and C)
G) B) and D)

Question 4

Which method often results in colonies developing down throughout the agar along with some colonies on the surface?

Accepted Answer

A)   Spread plate
B)   Pour plate
C)   Replica plate
D)   Streak plateE) B) and D)
F) B) and C)

Question 5

Which of the following is essential for the development of discrete,isolated colonies?

Accepted Answer

A)   Solid medium
B)   Differential medium
C)   Broth medium
D)   Assay medium
E)   Selective mediumF) All of the above
G) C) and D)

Question 6

Which of the following is not an inoculating tool?

Accepted Answer

A)   Pipette
B)   Swab
C)   Petri dish
D)   Loop
E)   NeedleF) D) and E)
G) A) and B)

Question 7

The Gram staining procedure is best described as a ______ staining technique.

Accepted Answer

A)   negative
B)   simple
C)   selective
D)   differentialE) B) and D)
F) A) and C)

Question 8

Following a properly-performed Gram stain,gram-positive bacteria will appear as pink or red cells.

Accepted Answer

A) True 
 B)False

Question 9

Fixed smears of specimens are required to perform the Gram stain or the endospore stain.

Accepted Answer

A) True 
 B)False

Question 10

Differential media result in which of the following observable characteristics?

Accepted Answer

A)   Differently colored colonies
B)   Different media color after incubation
C)   Chemical precipitates
D)   Gas bubbles
E)   All of the choices are correct.F) D) and E)
G) B) and C)

Question 11

Which type of medium would be the best choice when shipping a sample of bacteria from a clinic to a laboratory for testing?

Accepted Answer

A)   Thioglycolate medium
B)   Eosin-methylene blue agar
C)   Transport medium
D)   Blood agarE) A) and B)
F) None of the above

Question 12

A microbiologist makes a fixed smear of bacterial cells and stains it with methylene blue.All cells appear blue under the oil immersion lens.This is an example of ______.

Accepted Answer

A)   simple staining
B)   negative staining
C)   capsule staining
D)   the acid-fast stain
E)   using an acidic dyeF) B) and D)
G) None of the above

Question 13

A medium that is gel-like has less agar in it compared to a solid medium.

Accepted Answer

A) True 
 B)False

Question 14

A differential interference contrast microscope uses dyes to give colored,three-dimensional images.

Accepted Answer

A) True 
 B)False

Question 15

A reducing medium contains

Accepted Answer

A)   sugars that can be fermented.
B)   extra oxygen.
C)   hemoglobin, vitamins, or other growth factors.
D)   substances that remove oxygen.
E)   inhibiting agents.F) C) and D)
G) A) and E)

Question 16

A scanning confocal microscope

Accepted Answer

A)   produces specimen images on electron micrographs.
B)   uses dyes that emit visible light when excited by ultraviolet radiation.
C)   uses ultraviolet light to form a specimen image.
D)   scans narrow planes and can build a three-dimensional image of the specimen.E) All of the above
F) None of the above

Question 17

Which type of microscopy transforms the subtle variations in cell density into differences in light intensity,allowing for increased internal detail without staining?

Accepted Answer

A)   Electron
B)   Fluorescence
C)   Bright-field
D)   Confocal
E)   Phase-contrastF) B) and D)
G) None of the above

Question 18

Basic dyes are

Accepted Answer

A)   repelled by cells.
B)   attracted to the acidic surface of bacterial cells.
C)   used in negative staining.
D)   dyes such as India ink and nigrosin.
E)   anionic.F) A) and B)
G) A) and C)

Question 19

Which type of microscope shows cells against a white background?

Accepted Answer

A)   Confocal
B)   Electron
C)   Bright-field
D)   Fluorescence
E)   Phase-contrastF) B) and C)
G) B) and E)

Question 20

Your microscope has a resolving power of 0.15  μ\muμ m.The specimen that you will be observing has bacterial cocci the size of 0.1  μ\muμ m in diameter.Which of the following statements is correct?

Accepted Answer

A)   The cocci will appear much smaller than their actual size because of the low resolution.
B)   The cocci will be fuzzy-looking and blend together.
C)   The cocci will not be visible.
D)   The cocci will be readily visible and distinct. E) A) and B)
F) None of the above

Exam 3: Tools of the Laboratory: Methods for the Culturing of Microscopic Analysis of Microorganisms

Basic dyes are

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The type of microscopy in which you would observe brightly illuminated specimens against a black background is ______.

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Scattering of peripheral light rays through the glass slide under very high magnification can be prevented by ______.

Correct AnswerverifiedShow Answer

Which of the following is essential for the development of discrete,isolated colonies?

Correct AnswerverifiedShow Answer

A microbiologist makes a fixed smear of bacterial cells and stains it with methylene blue.All cells appear blue under the oil immersion lens.This is an example of ______.

Correct AnswerverifiedShow Answer

Which type of microscopy transforms the subtle variations in cell density into differences in light intensity,allowing for increased internal detail without staining?

Correct AnswerverifiedShow Answer

Thioglycolate medium contains the following: yeast extract,pancreatic digest of casein,glucose,L-cysteine,sodium chloride,sodium thioglycolate,and agar.It is considered a complex medium because

Correct AnswerverifiedShow Answer

A differential interference contrast microscope uses dyes to give colored,three-dimensional images.

Correct AnswerverifiedShow Answer

The Gram staining procedure is best described as a ______ staining technique.

Correct AnswerverifiedShow Answer

Following a properly-performed Gram stain,gram-positive bacteria will appear as pink or red cells.

Correct AnswerverifiedShow Answer

A medium that is gel-like has less agar in it compared to a solid medium.

Correct AnswerverifiedShow Answer

Which type of medium would be the best choice when shipping a sample of bacteria from a clinic to a laboratory for testing?

Correct AnswerverifiedShow Answer

Fixed smears of specimens are required to perform the Gram stain or the endospore stain.

Correct AnswerverifiedShow Answer

Which of the following is not an inoculating tool?

Correct AnswerverifiedShow Answer

Differential media result in which of the following observable characteristics?

Correct AnswerverifiedShow Answer

A scanning confocal microscope

Correct AnswerverifiedShow Answer

Which method often results in colonies developing down throughout the agar along with some colonies on the surface?

Correct AnswerverifiedShow Answer

Which type of microscope shows cells against a white background?

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Your microscope has a resolving power of 0.15 μ\muμ m.The specimen that you will be observing has bacterial cocci the size of 0.1 μ\muμ m in diameter.Which of the following statements is correct?

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A reducing medium contains

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Your microscope has a resolving power of 0.15 $\mu$ m.The specimen that you will be observing has bacterial cocci the size of 0.1 $\mu$ m in diameter.Which of the following statements is correct?

Correct Answer
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