Question 1

Newly inoculated cultures must be _____ at a specific temperature and time to encourage growth.

Accepted Answer

A)  incubated
B)  streaked
C)  spread
D)  poured

Question 2

Humans can see objects as small as 0.1 mm.Leeuwenhoek's best microscope could magnify objects to 300X.Which of the following would be invisible using Leeuwenhoek's microscope?

Accepted Answer

A)  Poliovirus, 30 nm
B)  Red blood cell, 8  μ\muμ m
C)  Escherichia coli, 1  μ\muμ m X 4  μ\muμ m
D)  Pandora virus, 0.5 mm X 1 mm

Question 3

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.

Question 4

Which of the following is not an inoculating tool?

Accepted Answer

A)  Pipette
B)  Swab
C)  Petri dish
D)  Loop
E)  Needle

Question 5

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-contrast

Question 6

A reducing medium is used to culture ______ organisms.

Accepted Answer

A)  fastidious
B)  pathogenic
C)  anaerobic
D)  aerobic

Question 7

Robert Koch and his colleagues first used agar in bacteriological media.Why was this ingredient an improvement on previous materials used to culture bacteria?

Accepted Answer

A)  Agar can convert from liquid to solid form, and back again, very easily.
B)  Agar is a complete source of nutrients for most bacteria.
C)  Bacteria growing on the solidified medium did not degrade or break down the agar.
D)  Agar was less expensive than the nutrients that Koch was previously using in the lab.

Question 8

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

Accepted Answer

A)  negative
B)  simple
C)  selective
D)  differential

Question 9

The simple microscopes used by the earliest practitioners of microscopy contained which of the following?

Accepted Answer

A)  Magnifying lens
B)  Oil-immersion lens
C)  Lamp
D)  Ocular
E)  Condenser

Question 10

The bacterium Neisseria gonorrhoeae causes the sexually-transmitted infection gonorrhea.Although it can be isolated from the vagina, there are numerous normal biota in that location as well.To generate a pure culture of this pathogenic bacterium, the best choice is a(n)  ______.

Accepted Answer

A)  differential medium
B)  enrichment medium
C)  selective medium
D)  liquid medium

Question 11

If a microbiologist is studying a specimen at a total magnification of 950X, what is the magnifying power of the objective lens if the ocular lens is 10X?

Accepted Answer

A)  95X
B)  940X
C)  950X
D)  9500X

Question 12

The purpose of staining cells on a microscope slide is to ______.

Accepted Answer

A)  secure them to the slide
B)  kill them
C)  observe motility
D)  enlarge the cells
E)  add contrast to see them better

Question 13

A microbiologist inoculates Staphylococcus aureus into a culture medium.Following incubation, both Staphylococcus aureus and Staphylococcus epidermidis are determined to be growing in this culture.What is the most likely explanation?

Accepted Answer

A)  The microbiologist used too much inoculum.
B)  The culture medium was selective.
C)  The culture medium was differential.
D)  The culture was contaminated.
E)  The incubation temperature was incorrect.

Question 14

The wavelength of light used and the numerical aperture governs ______.

Accepted Answer

A)  resolution
B)  contrast
C)  illumination
D)  size of the field
E)  magnification

Question 15

Which of the following is produced by adding 1% to 5% agar to nutrient broth that is then boiled and cooled?

Accepted Answer

A)  A pure culture
B)  A contaminated medium
C)  A liquid medium
D)  A mixed culture
E)  A solid medium

Question 16

Mixed cultures are also referred to as contaminated cultures.

Accepted Answer

A) True 
 B)False

Question 17

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

Accepted Answer

A) True 
 B)False

Question 18

Mannitol salt agar is selective for organisms in which bacterial genus?

Accepted Answer

A)  Salmonella
B)  Staphylococcus
C)  Escherichia
D)  Neisseria
E)  Streptococcus

Question 19

A microbiologist must culture a patient's feces for intestinal pathogens.Which of the following components would likely be present in a selective medium for this purpose?

Accepted Answer

A)  Thioglycolic acid
B)  Sheep red blood cells
C)  Bile salts
D)  Peptone
E)  NaCl

Question 20

Eosin-methylene blue agar, or EMB, is a commonly used bacteriological medium for growing gram-negative bacteria from complex environments.It contains two dyes, eosin and methylene blue, as well as the sugar lactose.Eosin is a pH indicator that changes color when the medium is acidic, while methylene blue inhibits the growth of most gram-positive bacteria.If an organism consumes lactose, acid will be produced, causing the bacterial colonies to change color. Based upon this description, this medium is ______.

Accepted Answer

A)  reducing
B)  for enrichment
C)  selective
D)  differential and selective
E)  differential

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

Correct Answer
verified

The wavelength of light used and the numerical aperture governs ______.

Correct Answer
verified

A reducing medium is used to culture ______ organisms.

Correct Answer
verified

A microbiologist inoculates Staphylococcus aureus into a culture medium.Following incubation, both Staphylococcus aureus and Staphylococcus epidermidis are determined to be growing in this culture.What is the most likely explanation?

Correct Answer
verified

The purpose of staining cells on a microscope slide is to ______.

Correct Answer
verified

Basic dyes are

Correct Answer
verified

The bacterium Neisseria gonorrhoeae causes the sexually-transmitted infection gonorrhea.Although it can be isolated from the vagina, there are numerous normal biota in that location as well.To generate a pure culture of this pathogenic bacterium, the best choice is a(n) ______.

Correct Answer
verified

The simple microscopes used by the earliest practitioners of microscopy contained which of the following?

Correct Answer
verified

Newly inoculated cultures must be _____ at a specific temperature and time to encourage growth.

Correct Answer
verified

Which of the following is not an inoculating tool?

Correct Answer
verified

A microbiologist must culture a patient's feces for intestinal pathogens.Which of the following components would likely be present in a selective medium for this purpose?

Correct Answer
verified

If a microbiologist is studying a specimen at a total magnification of 950X, what is the magnifying power of the objective lens if the ocular lens is 10X?

Correct Answer
verified

Robert Koch and his colleagues first used agar in bacteriological media.Why was this ingredient an improvement on previous materials used to culture bacteria?

Correct Answer
verified

Which of the following is produced by adding 1% to 5% agar to nutrient broth that is then boiled and cooled?

Correct Answer
verified

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

Correct Answer
verified

Humans can see objects as small as 0.1 mm.Leeuwenhoek's best microscope could magnify objects to 300X.Which of the following would be invisible using Leeuwenhoek's microscope?

Correct Answer
verified

Mannitol salt agar is selective for organisms in which bacterial genus?

Correct Answer
verified

Mixed cultures are also referred to as contaminated cultures.

Correct Answer
verified

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

Correct Answer
verified

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

Correct Answer
verified

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

Correct AnswerverifiedShow Answer

The wavelength of light used and the numerical aperture governs ______.

Correct AnswerverifiedShow Answer

A reducing medium is used to culture ______ organisms.

Correct AnswerverifiedShow Answer

A microbiologist inoculates Staphylococcus aureus into a culture medium.Following incubation, both Staphylococcus aureus and Staphylococcus epidermidis are determined to be growing in this culture.What is the most likely explanation?

Correct AnswerverifiedShow Answer

The purpose of staining cells on a microscope slide is to ______.

Correct AnswerverifiedShow Answer

Basic dyes are

Correct AnswerverifiedShow Answer

The bacterium Neisseria gonorrhoeae causes the sexually-transmitted infection gonorrhea.Although it can be isolated from the vagina, there are numerous normal biota in that location as well.To generate a pure culture of this pathogenic bacterium, the best choice is a(n) ______.

Correct AnswerverifiedShow Answer

The simple microscopes used by the earliest practitioners of microscopy contained which of the following?

Correct AnswerverifiedShow Answer

Newly inoculated cultures must be _____ at a specific temperature and time to encourage growth.

Correct AnswerverifiedShow Answer

Which of the following is not an inoculating tool?

Correct AnswerverifiedShow Answer

A microbiologist must culture a patient's feces for intestinal pathogens.Which of the following components would likely be present in a selective medium for this purpose?

Correct AnswerverifiedShow Answer

If a microbiologist is studying a specimen at a total magnification of 950X, what is the magnifying power of the objective lens if the ocular lens is 10X?

Correct AnswerverifiedShow Answer

Robert Koch and his colleagues first used agar in bacteriological media.Why was this ingredient an improvement on previous materials used to culture bacteria?

Correct AnswerverifiedShow Answer

Which of the following is produced by adding 1% to 5% agar to nutrient broth that is then boiled and cooled?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Humans can see objects as small as 0.1 mm.Leeuwenhoek's best microscope could magnify objects to 300X.Which of the following would be invisible using Leeuwenhoek's microscope?

Correct AnswerverifiedShow Answer

Mannitol salt agar is selective for organisms in which bacterial genus?

Correct AnswerverifiedShow Answer

Mixed cultures are also referred to as contaminated cultures.

Correct AnswerverifiedShow Answer

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

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

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