Question 1

Microbes were detected long before the invention of the microscope. How could this be?

Accepted Answer

Detection is the ability to observe the presence of an object, such as when we detect a group of bacteria in a culture tube or growing on a surface such as a food product. Even though we can detect the group, we cannot resolve individual cells without the magnification afforded by microscopes.

Question 2

One advantage of a wet mount is

Accepted Answer

A)   low contrast.
B)   that the organism is still.
C)   viewing in a natural state.
D)   high contrast.
E)   that the sample does not overheat.F) A) and C)
G) All of the above

Question 3

List and describe three common shapes of bacteria.

Accepted Answer

Bacilli (bacillus in the singu...

Question 4

Compare and contrast the radiation sources, lenses, and image-capturing devices used in light microscopy and transmission electron microscopy.

Accepted Answer

The radiation source for light microscop...

Question 5

Why do some bacteria appear purple after being Gram stained, while others appear pink?

Accepted Answer

Gram-negative cells have a few layers of peptidoglycan cell wall and an outer lipopolysaccharide membrane. Gram-positive organisms have several layers of peptidoglycan and no outer membrane. The multiple layers of peptidoglycan retain the crystal violet-iodine complex, so appear purple. Gram-negative cells do not retain the crystal violet because there are few layers of peptidoglycan and the outer membrane is disrupted by the decolorizer.

Question 6

Compare and contrast a simple stain (like methylene blue) with the Gram stain. What information about a microbial sample can be collected with each?

Accepted Answer

Both staining procedures colorize bacter...

Question 7

When two waves are out of phase by ________ wavelength, they produce destructive interference, canceling each other's amplitude and resulting in contrast in the image.

Accepted Answer

A)   one-tenth of a
B)   one-eighth of a
C)   one-quarter of a
D)   one-half of a
E)   oneF) B) and C)
G) B) and D)

Question 8

Malachite green is commonly used to stain

Accepted Answer

A)   eukaryotic cells.
B)   Gram-negative cells.
C)   Gram-positive cells.
D)   bacterial endospores.
E)   acid-fast cells.F) C) and D)
G) A) and D)

Question 9

Which of these techniques can be used to localize the DNA sequence at the origin of replication in a bacterial cell?

Accepted Answer

A)   fluorescence microscopy
B)   phase contrast
C)   X-ray diffraction
D)   atomic force microscopy
E)   cryo-EMF) C) and D)
G) None of the above

Question 10

If aqueous cytoplasm was submerged in a beaker of immersion oil, the slide would be

Accepted Answer

A)   undetectable.
B)   brighter than its surroundings.
C)   darker than its surroundings.
D)   fluorescent.
E)   stained.F) C) and D)
G) A) and C)

Question 11

Are all bacilli Bacillus? Explain.

Accepted Answer

No. Bacillus refers to a particular genu...

Question 12

Using the figure below, explain how the visualization of molecules occurs through X-ray crystallography.

Accepted Answer

The X-ray beam focuses on a crystal and ...

Question 13

Define a fluorophore and give three examples of how it can be used to label cells.

Accepted Answer

A fluorophore is a fluorescent molecule ...

Question 14

Which of the following is an advantage of using chemical imaging microscopy?

Accepted Answer

A)   observing an organism in its living environment
B)   displaying plankton
C)   measuring pH within a cell
D)   showing distribution of chemicals in a cell
E)   pinpointing a protein locationF) A) and C)
G) B) and E)

Question 15

Which of the following is best visualized using a negative stain?

Accepted Answer

A)   Gram-negative cell wall
B)   acid-fast cell wall
C)   capsule
D)   endospores
E)   flagellaF) A) and E)
G) A) and D)

Question 16

Fluorescence microscopy using labeled antibodies is referred to as

Accepted Answer

A)   immunofluorescence.
B)   autofluorescence.
C)   confocal microscopy.
D)   phase-contrast microscopy.
E)   dark-field microscopy.F) A) and B)
G) A) and C) A

Question 17

Cryo-electron microscopy (cryo-EM)  is differentiated from transmission electron microscopy because it

Accepted Answer

A)   requires making thin slices of the sample to be viewed.
B)   does not require staining with heavy metals.
C)   may be used to view living tissues.
D)   uses a weaker electron beam.
E)   can provide a color image of the microbial cell.F) A) and C)
G) B) and E)

Question 18

Fluorescent microscopy that absorbs light at 260m would MOST likely fluoresce at

Accepted Answer

A)   100 nm.
B)   200 nm.
C)   260 nm.
D)   400 nm.
E)   800 nm.F) B) and C)
G) A) and E)

Question 19

Which type of microscopy is used to identify the 3-D structure of biofilms?

Accepted Answer

A)   phase-contrast
B)   dark-field
C)   florescent
D)   bright-field
E)   confocalF) All of the above
G) B) and D)

Question 20

What is the MOST important property that enables a lens to magnify an image?

Accepted Answer

A)   absorption
B)   fluorescence
C)   reflection
D)   refraction
E)   scatteringF) B) and E)
G) C) and D)

Exam 2: Observing the Microbial Cell

Microbes were detected long before the invention of the microscope. How could this be?

One advantage of a wet mount is

Correct Answer
verified

List and describe three common shapes of bacteria.

Correct Answer
verified
Bacilli (bacillus in the singu...
View Answer

Compare and contrast the radiation sources, lenses, and image-capturing devices used in light microscopy and transmission electron microscopy.

Correct Answer
verified
The radiation source for light microscop...
View Answer

Why do some bacteria appear purple after being Gram stained, while others appear pink?

Compare and contrast a simple stain (like methylene blue) with the Gram stain. What information about a microbial sample can be collected with each?

Correct Answer
verified
Both staining procedures colorize bacter...
View Answer

When two waves are out of phase by ________ wavelength, they produce destructive interference, canceling each other's amplitude and resulting in contrast in the image.

Correct Answer
verified

Malachite green is commonly used to stain

Correct Answer
verified

Which of these techniques can be used to localize the DNA sequence at the origin of replication in a bacterial cell?

Correct Answer
verified

If aqueous cytoplasm was submerged in a beaker of immersion oil, the slide would be

Correct Answer
verified

Are all bacilli Bacillus? Explain.

Correct Answer
verified
No. Bacillus refers to a particular genu...
View Answer

Using the figure below, explain how the visualization of molecules occurs through X-ray crystallography.

Correct Answer
verified
The X-ray beam focuses on a crystal and ...
View Answer

Define a fluorophore and give three examples of how it can be used to label cells.

Correct Answer
verified
A fluorophore is a fluorescent molecule ...
View Answer

Which of the following is an advantage of using chemical imaging microscopy?

Correct Answer
verified

Which of the following is best visualized using a negative stain?

Correct Answer
verified

Fluorescence microscopy using labeled antibodies is referred to as

Correct Answer
verified
A

Cryo-electron microscopy (cryo-EM) is differentiated from transmission electron microscopy because it

Correct Answer
verified

Fluorescent microscopy that absorbs light at 260m would MOST likely fluoresce at

Correct Answer
verified

Which type of microscopy is used to identify the 3-D structure of biofilms?

Correct Answer
verified

What is the MOST important property that enables a lens to magnify an image?

Correct Answer
verified

Exam 2: Observing the Microbial Cell

Microbes were detected long before the invention of the microscope. How could this be?

One advantage of a wet mount is

Correct AnswerverifiedShow Answer

List and describe three common shapes of bacteria.

Correct AnswerverifiedBacilli (bacillus in the singu...View AnswerShow Answer

Compare and contrast the radiation sources, lenses, and image-capturing devices used in light microscopy and transmission electron microscopy.

Correct AnswerverifiedThe radiation source for light microscop...View AnswerShow Answer

Why do some bacteria appear purple after being Gram stained, while others appear pink?

Compare and contrast a simple stain (like methylene blue) with the Gram stain. What information about a microbial sample can be collected with each?

Correct AnswerverifiedBoth staining procedures colorize bacter...View AnswerShow Answer

When two waves are out of phase by ________ wavelength, they produce destructive interference, canceling each other's amplitude and resulting in contrast in the image.

Correct AnswerverifiedShow Answer

Malachite green is commonly used to stain

Correct AnswerverifiedShow Answer

Which of these techniques can be used to localize the DNA sequence at the origin of replication in a bacterial cell?

Correct AnswerverifiedShow Answer

If aqueous cytoplasm was submerged in a beaker of immersion oil, the slide would be

Correct AnswerverifiedShow Answer

Are all bacilli Bacillus? Explain.

Correct AnswerverifiedNo. Bacillus refers to a particular genu...View AnswerShow Answer

Using the figure below, explain how the visualization of molecules occurs through X-ray crystallography.

Correct AnswerverifiedThe X-ray beam focuses on a crystal and ...View AnswerShow Answer

Define a fluorophore and give three examples of how it can be used to label cells.

Correct AnswerverifiedA fluorophore is a fluorescent molecule ...View AnswerShow Answer

Which of the following is an advantage of using chemical imaging microscopy?

Correct AnswerverifiedShow Answer

Which of the following is best visualized using a negative stain?

Correct AnswerverifiedShow Answer

Fluorescence microscopy using labeled antibodies is referred to as

Correct AnswerverifiedA

Cryo-electron microscopy (cryo-EM) is differentiated from transmission electron microscopy because it

Correct AnswerverifiedShow Answer

Fluorescent microscopy that absorbs light at 260m would MOST likely fluoresce at

Correct AnswerverifiedShow Answer

Which type of microscopy is used to identify the 3-D structure of biofilms?

Correct AnswerverifiedShow Answer

What is the MOST important property that enables a lens to magnify an image?

Correct AnswerverifiedShow Answer

Correct Answer
verified

Correct Answer
verified
Bacilli (bacillus in the singu...
View Answer

Correct Answer
verified
The radiation source for light microscop...
View Answer

Correct Answer
verified
Both staining procedures colorize bacter...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
No. Bacillus refers to a particular genu...
View Answer

Correct Answer
verified
The X-ray beam focuses on a crystal and ...
View Answer

Correct Answer
verified
A fluorophore is a fluorescent molecule ...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
A

Correct Answer
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Correct Answer
verified

Correct Answer
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Correct Answer
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