Question 1

What is the best explanation for a Gram-negative bacterium appearing purple after performing a Gram stain?

Accepted Answer

A)   The safranin was not applied.
B)   The decolorizer was not applied.
C)   The iodine was not applied.
D)   The crystal violet was not applied.
E)   The stain was properly performed.F) B) and D)
G) A) and E)

Question 2

As lens strength increases, the light cone ________ and the lens must be ________ the object.

Accepted Answer

A)   narrows; nearer to
B)   narrows; farther from
C)   widens; nearer to
D)   widens; farther from
E)   widens; touchingF) B) and E)
G) A) and B)

Question 3

Atomic force microscopy measures ________ between a probe and an object to map the three-dimensional topography of a cell.

Accepted Answer

A)   hydrogen bonds
B)   covalent interactions
C)   van der Waals forces
D)   pH changes
E)   magnetic interactionsF) A) and B)
G) D) and E)

Question 4

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) A) and D)
G) All of the above

Question 5

Resolution is the smallest distance by which two objects can be ________ and still be ________.

Accepted Answer

A)   magnified; seen
B)   separated; distinguished
C)   magnified; separated
D)   distinguished; separated
E)   magnified; distinguishedF) All of the above
G) A) and E)

Question 6

What happens to an electron when excited by light at the excitation wavelength?

Accepted Answer

A)   It remains in the same orbital.
B)   It moves to a lower energy orbital.
C)   It moves to a higher energy orbital.
D)   It emits a photon.
E)   It is filtered.F) B) and D)
G) D) and E)

Question 7

Which of these arranges the steps of the Gram stain into the correct order?

Accepted Answer

A)   iodine crystal violet decolorizer safranin
B)   safranin decolorizer crystal violet iodine
C)   crystal violet decolorizer iodine safranin
D)   crystal violet decolorizer safranin iodine
E)   crystal violet iodine decolorizer safraninF) B) and E)
G) C) and D)

Question 8

What happens if the wavelength of radiation is larger than the object being viewed?

Accepted Answer

A)   absorption
B)   scattering
C)   no resolution
D)   refraction
E)   resolutionF) B) and D)
G) C) and E)

Question 9

The digitally combined images of cryo-EM can achieve resolution comparable to that of

Accepted Answer

A)   scanning electron microscopy.
B)   transmission electron microscopy.
C)   interference microscopy.
D)   X-ray crystallography.
E)   dark-field microscopy.F) All of the above
G) A) and B)

Question 10

List three different differential stains used in microbiology. What can be detected with each?

Accepted Answer

The most common differential stain is th...

Question 11

Label the condenser in the figure below.

Accepted Answer

A)   A
B)   B
C)   C
D)   D
E)   EF) A) and E)
G) All of the above

Question 12

Which of the following would be MOST appropriate to visualize viral particles being assembled inside an infected bacterial cell?

Accepted Answer

A)   dark-field microscopy
B)   atomic force microscopy
C)   fluorescence microscopy
D)   scanning electron microscopy
E)   transmission electron microscopyF) C) and E)
G) B) and E)

Question 13

List and briefly describe four ways that light interacts with objects.

Accepted Answer

(1) Absorption: light energy is absorbed...

Question 14

Which of these numeric aperture and light combinations would give the best resolution?

Accepted Answer

A)   numeric aperture = 0.8, wavelength = 600 nm
B)   numeric aperture = 0.8, wavelength = 500 nm
C)   numeric aperture = 1.0, wavelength = 700 nm
D)   numeric aperture = 1.0, wavelength = 600 nm
E)   numeric aperture = 0.8, wavelength = 400 nmF) A) and D)
G) A) and B)

Question 15

What molecule is shown below?

Accepted Answer

A)   GFP
B)   FM4-64
C)   DNA
D)   RNA
E)   DAPIF) A) and B)
G) B) and C)

Question 16

Increasing the refractive index of the medium between the object and the objective lens increases

Accepted Answer

A)   refraction.
B)   reflection.
C)   magnification.
D)   resolution.
E)   wavelength.F) None of the above
G) A) and B)

Question 17

Why are stains used in microscopy? Compare and contrast the stains used in light versus electron microscopy.

Accepted Answer

Stains are used to increase the contrast...

Question 18

Staining helps to visualize bacteria by increasing the

Accepted Answer

A)   size of the cells.
B)   motility of the cells.
C)   contrast of the image.
D)   magnification of the image.
E)   aberration of the image.F) C) and D)
G) B) and E)

Question 19

Explain why components from thermophilic bacteria take less X-ray damage than other bacteria.

Accepted Answer

There is always unavoidable deterioratio...

Question 20

What would happen if a lens had the same refractive index as air?

Accepted Answer

A)   Light would not pass through the lens.
B)   The image would be magnified more than with a glass lens.
C)   The image would be magnified, but the resolution would be less than with a glass lens.
D)   The image would be magnified, and the resolution would be greater than with a glass lens.
E)   The image would not be magnified.F) A) and C)
G) None of the above

Exam 2: Observing the Microbial Cell

Which of the following would be MOST appropriate to visualize viral particles being assembled inside an infected bacterial cell?

Correct AnswerverifiedShow Answer

Why are stains used in microscopy? Compare and contrast the stains used in light versus electron microscopy.

Correct AnswerverifiedStains are used to increase the contrast...View AnswerShow Answer

Which of these arranges the steps of the Gram stain into the correct order?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

List and briefly describe four ways that light interacts with objects.

Correct Answerverified(1) Absorption: light energy is absorbed...View AnswerShow Answer

Increasing the refractive index of the medium between the object and the objective lens increases

Correct AnswerverifiedShow Answer

What happens if the wavelength of radiation is larger than the object being viewed?

Correct AnswerverifiedShow Answer

What happens to an electron when excited by light at the excitation wavelength?

Correct AnswerverifiedShow Answer

List three different differential stains used in microbiology. What can be detected with each?

Correct AnswerverifiedThe most common differential stain is th...View AnswerShow Answer

Explain why components from thermophilic bacteria take less X-ray damage than other bacteria.

Correct AnswerverifiedThere is always unavoidable deterioratio...View AnswerShow Answer

The digitally combined images of cryo-EM can achieve resolution comparable to that of

Correct AnswerverifiedShow Answer

Label the condenser in the figure below.

Correct AnswerverifiedShow Answer

What is the best explanation for a Gram-negative bacterium appearing purple after performing a Gram stain?

Correct AnswerverifiedShow Answer

What molecule is shown below?

Correct AnswerverifiedShow Answer

Resolution is the smallest distance by which two objects can be ________ and still be ________.

Correct AnswerverifiedShow Answer

Which of these numeric aperture and light combinations would give the best resolution?

Correct AnswerverifiedShow Answer

What would happen if a lens had the same refractive index as air?

Correct AnswerverifiedShow Answer

As lens strength increases, the light cone ________ and the lens must be ________ the object.

Correct AnswerverifiedShow Answer

Staining helps to visualize bacteria by increasing the

Correct AnswerverifiedShow Answer

Atomic force microscopy measures ________ between a probe and an object to map the three-dimensional topography of a cell.

Correct AnswerverifiedShow Answer

Correct Answer
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Correct Answer
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Stains are used to increase the contrast...
View Answer

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Correct Answer
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Correct Answer
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(1) Absorption: light energy is absorbed...
View Answer

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Correct Answer
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Correct Answer
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Correct Answer
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The most common differential stain is th...
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Correct Answer
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There is always unavoidable deterioratio...
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Correct Answer
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Correct Answer
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Correct Answer
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Resolution is the smallest distance by which two objects can be and still be .

Correct Answer
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Correct Answer
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Correct Answer
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As lens strength increases, the light cone and the lens must be the object.

Correct Answer
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Correct Answer
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Correct Answer
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