Question 1

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

Question 2

All of the following are examples of different types of microbiological media except ______.

Accepted Answer

A)   agar
B)   Petri dish
C)   broth
D)   semisolid
E)   enriched

Question 3

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

Question 4

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

Accepted Answer

A)   Solid medium
B)   Selective medium
C)   Broth medium
D)   Differential medium
E)   Assay medium

Question 5

Bacterial cultures are easily identiﬁed from their microscopic appearance.

Accepted Answer

A) True 
 B)False

Question 6

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

Accepted Answer

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

Question 7

A common medium for culturing fastidious bacteria is ______.

Accepted Answer

A)   MacConkey medium
B)   trypticase soy agar
C)   blood agar
D)   mannitol salt agar
E)   reducing medium

Question 8

Which type of microscope shows cells against a white background?

Accepted Answer

A)   Electron
B)   Bright-ﬁeld
C)   Confocal
D)   Phase-contrast
E)   Fluorescence

Question 9

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)   Blood agar
B)   Transport medium
C)   Eosin-methylene blue agar
D)   Thioglycolate medium

Question 10

A nutrient medium that has all of its chemical components identiﬁed and their precise concentrations known and reproducible is termed ______.

Accepted Answer

A)   enriched
B)   deﬁned
C)   reducing
D)   complex

Question 11

The procedures for culturing a microorganism require the use of a microscope.

Accepted Answer

A) True 
 B)False

Question 12

Cells of Staphylococcus aureus are cocci measuring about 1 ?m in diameter. In a textbook image of S. aureus, each cell measures about 1 cm. The magni?cation of the image on the page is ______.

Accepted Answer

A)   10,000X
B)   1,000X
C)   100X
D)   0.01X
E)   0.001X F) 0.0001X

Question 13

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

Question 14

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

Question 15

Bacteria that require special growth factors and complex nutrients are termed ______.

Accepted Answer

A)   fermentative
B)   aerobic
C)   hemolytic
D)   anaerobic
E)   fastidious

Question 16

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

Accepted Answer

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

Question 17

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/an ______.

Accepted Answer

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

Question 18

Which of the following parts of a microscope magniﬁes the specimen to produce a real image of the specimen?

Accepted Answer

A)   Nosepiece
B)   Objective lens
C)   Ocular lens
D)   Body
E)   Condenser

Question 19

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

Question 20

All of the following are diameters of cells that would be resolved in a microscope with a limit of resolution of 0.2 µm except ______.

Accepted Answer

A)   2.0 µm
B)   0.1 µm
C)   0.2 µm
D)   0.2 mm

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

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

A common medium for culturing fastidious bacteria is ______.

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

Which type of microscope shows cells against a white background?

Correct AnswerverifiedShow Answer

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

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

Cells of Staphylococcus aureus are cocci measuring about 1 ?m in diameter. In a textbook image of S. aureus, each cell measures about 1 cm. The magni?cation of the image on the page is ______.

Correct AnswerverifiedShow Answer

The procedures for culturing a microorganism require the use of a microscope.

Correct AnswerverifiedShow Answer

A reducing medium contains _______.

Correct AnswerverifiedShow Answer

Bacterial cultures are easily identiﬁed from their microscopic appearance.

Correct AnswerverifiedShow Answer

A nutrient medium that has all of its chemical components identiﬁed and their precise concentrations known and reproducible is termed ______.

Correct AnswerverifiedShow Answer

All of the following are diameters of cells that would be resolved in a microscope with a limit of resolution of 0.2 µm except ______.

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

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

Correct AnswerverifiedShow Answer

Which of the following parts of a microscope magniﬁes the specimen to produce a real image of the specimen?

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/an ______.

Correct AnswerverifiedShow Answer

Bacteria that require special growth factors and complex nutrients are termed ______.

Correct AnswerverifiedShow Answer

All of the following are examples of different types of microbiological media except ______.

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

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

Correct AnswerverifiedShow Answer

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