Question 1

Which of the following media is useful for cultivating fungi?

Accepted Answer

A) Sabouraud's agar 
B) MacConkey agar 
C) tomato juice agar 
D) phenylethanol agar 
E) Mueller tellurite

Question 2

A microbiologist makes a fixed smear of bacterial cells and stains them with Loeffler's methylene blue.All the cells appear blue under the oil lens.This is an example of

Accepted Answer

A) negative staining. 
B) using an acidic dye. 
C) simple staining. 
D) using the acid-fast stain. 
E) capsule staining.

Question 3

Microbes can be challenging to study because they often grow in complex communities and it may be difficult to separate the various species from one another to study individually.Which of the following laboratory "tools" or techniques may be of the the most help with separating out different species from complex mixtures?

Accepted Answer

A) use of transmission electron microscopy 
B) use of enriched agar for culture 
C) use of selective agars for culture 
D) use of light microscopy

Question 4

A media is designed that allows only staphylococci to grow.In addition, S.aureus colonies have a yellow halo around them and other staphylococci appear white.This type of media is

Accepted Answer

A) selective only. 
B) differential only. 
C) both selective and differential. 
D) a reducing media. 
E) enriched.

Question 5

Which of the following characteristics refers to the microscope's ability to show two separate entities as separate and distinct?

Accepted Answer

A) resolving power 
B) magnification 
C) refraction 
D) All of these choices are correct.

Question 6

The three physical forms of laboratory media are: solid, semisolid, and _____.

Accepted Answer

The answer of The three physical forms of laboratory media...

Question 7

Mannitol salt agar is selective for which bacterial genus?

Accepted Answer

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

Question 8

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) 100X 
B) 950X 
C) 85X 
D) 850X 
E) 95X

Question 9

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

Accepted Answer

A) broth. 
B) enriched. 
C) agar. 
D) Petri dish. 
E) gelatin.

Question 10

A microbiologist inoculates Staphylococcus epidermidis and Escherichia coli into a culture medium.Following incubation, only the E.coli grows in the culture.What is the most likely explanation?

Accepted Answer

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

Question 11

Which microscope bombards a whole, metal-coated specimen with electrons moving back and forth over it?

Accepted Answer

A) fluorescence 
B) differential interference contrast 
C) scanning electron 
D) transmission electron 
E) phase-contrast

Question 12

The Gram stain, acid-fast stain, and endospore stain ____________.

Accepted Answer

A) are used on a wet mount of the specimen 
B) use heat to force the dye into cell structures 
C) have outcomes based on cell wall differences 
D) use a negative stain technique 
E) are differential stains

Question 13

The bending of light rays as they pass from one medium to another is called refraction.

Accepted Answer

A) True 
 B)False

Question 14

Which type of media can be used to determine if a bacteria is motile?

Accepted Answer

A) SIM 
B) MacConkey 
C) enriched media 
D) Thayer-Martin media 
E) chocolate agar

Question 15

A selective medium contains one or more substances that inhibit growth of certain microbes in order to facilitate the growth of other microbes.

Accepted Answer

A) True 
 B)False

Question 16

How will E. coli appear if the mordant is not applied?

Accepted Answer

A) gram-positive 
B) gram-negative 
C) gram-variable 
D) colorless

Question 17

Compare and contrast the reagents and functions of negative staining versus positive staining.

Accepted Answer

The answer of Compare and contrast the reagents and functions...

Question 18

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 19

_____ dyes have a negative charge on the chromophore and are repelled by bacterial cells.

Accepted Answer

The answer of _____ dyes have a negative charge on...

Question 20

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

Accepted Answer

The answer of Bacteria that require special growth factors and...

Exam 3: Tools of the Laboratory: Methods of Studying Microorganisms