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

Question 1

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

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

Answer 1

D

Question 2

Which method often results in colonies developing down throughout the agar along with some colonies on the surface?

A)streak plate
B)spread plate
C)pour plate
D)replica plate

Answer 2

C

Question 3

The correct microbiological term for the tiny sample of specimen that is put into a nutrient medium in order to produce a culture is

A)colony.
B)inoculum.
C)streak.
D)loop.

Answer 3

B

Question 4

A microbiologist decides to use a nutrient medium that contains thioglycollic acid.What type of microbe is she attempting to culture?

A)fastidious
B)gram-positive
C)anaerobic
D)gram-negative
E)aerobic

Question 5

The Five I's of studying microorganisms include all of the following except

A)inoculation.
B)incubation.
C)infection.
D)isolation.
E)identification.

Question 6

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

A)complex.
B)reducing.
C)enriched.
D)synthetic.

Question 7

A reducing medium contains

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 8

Which of the following is not a benefit of agar as a solid medium?

A)flexibility
B)holds moisture
C)can be inoculated and poured at a temperature that is not harmful
D)solid at room temperature
E)digested by most microbes

Question 9

A common medium used for growing fastidious bacteria is

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

Question 10

Which isolation technique is most effective for the majority of applications,and is most commonly used for colony isolation in the laboratory?

A)pour plate
B)streak plate
C)spread plate
D)loop dilution
E)culture plate

Question 11

Which type of medium is able to distinguish different species or types of microorganisms based on an observable change in the colonies or in the medium?

A)differential
B)selective
C)enumeration
D)enriched
E)reducing

Question 12

Which of the following is not an inoculating tool?

A)Petri dish
B)loop
C)needle
D)pipette
E)swab

Question 13

The term that refers to the purposeful addition of microorganisms into a laboratory nutrient medium is

A)isolation.
B)inoculation.
C)immunization.
D)infection.
E)contamination.

Question 14

Agar is an important component of media because

A)bacteria require agar to grow.
B)agar inhibits mold growth.
C)agar provides a solid surface for bacterial growth.
D)agar prevents contamination.

Question 15

A pure culture contains

A)only one identified species of microorganism.
B)only bacteria.
C)a variety of microbes from one source.
D)a variety of species from the same genus.

Question 16

A nutrient medium that contains at least one ingredient that is not chemically definable is termed

A)complex.
B)reducing.
C)enriched.
D)synthetic.

Question 17

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

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

Question 18

Agar is a complex polysaccharide that comes from a/an

A)green plant.
B)fungus.
C)mold.
D)algae.
E)Euglena.

Question 19

The three physical forms of laboratory media are

A)solid,liquid,and gas.
B)solid,semisolid,and liquid.
C)streak plate,pour plate,and broth.
D)aerobic,anaerobic,and microaerobic.

Question 20

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

A)broth medium
B)differential medium
C)selective medium
D)solid medium
E)assay medium

Question 21

Bacteria that require special growth factors and complex nutrients are termed

A)aerobic.
B)anaerobic.
C)fastidious.
D)microaerophilic.
E)autotrophic.

Question 22

The wavelength of light used and the numerical aperture governs

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

Question 23

A microbiologist must culture a patient's feces for intestinal pathogens.Which of the following would likely be present in selective media for analyzing this fecal specimen?

A)NaCl
B)sheep red blood cells
C)bile salts
D)thioglycollic acid
E)peptone

Question 24

Which of the following controls the amount of light entering the condenser?

A)objective lens
B)ocular lens
C)condenser
D)body
E)iris diaphragm

Question 25

For which bacterial genus is mannitol salt agar selective?

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

Question 26

A reducing medium is used to culture

A)fastidious organisms.
B)aerobic organisms.
C)anaerobic organisms.
D)any pathogenic organisms.

Question 27

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

A)condenser
B)objective lens
C)ocular lens
D)body
E)nosepiece

Question 28

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?

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 29

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

A)resolving power
B)magnification
C)refraction
D)magnification

Question 30

The type of microscope in which you would see brightly illuminated specimens against a black background is

A)bright-field.
B)dark-field.
C)phase-contrast.
D)fluorescence.
E)electron.

Question 31

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

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

Question 32

What is the term for a culture made from one isolated colony?

A)axenic
B)mixed
C)pure
D)Both axenic and mixed are correct.
E)Both axenic and pure are correct.

Question 33

_____ has the same optical qualities as glass and thus prevents refractive loss of light as it passes from the slide to the objective lens.

A)The scanning objective
B)The oil objective
C)The slide
D)Immersion oil
E)The ocular

Question 34

Fluoresence microscopy uses a different wavelength of light to illuminate a specimen versus other types of microscopes.This results in:

A)more magnification
B)better resolution
C)less refraction
D)more distortion of the object
E)halos around the objects

Question 35

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

A)0.2 µm.
B)0.2 mm.
C)0.1 µm.
D)0.3 µm.
E)2.0 µm.

Question 36

Which of the following magnifies the specimen to produce the virtual image of the specimen?

A)objective lens
B)ocular lens
C)condenser
D)body
E)iris diaphragm

Question 37

Differential media result in which of the following growth characteristics?

A)different color colonies
B)different media color post incubation
C)precipitates
D)gas bubbles
E)All of the choices are correct.

Question 38

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?

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

Question 39

Magnification is achieved in a compound microscope through the initial magnification of the specimen by the _____ lens.This image is then projected to the _____ lens that will further magnify the specimen to form a virtual image received by the eye.

A)ocular;objective
B)scanning;objective
C)objective;ocular
D)ocular;oil immersion

Question 40

The _____ of the microscope holds and allows selection of the objective lenses.

A)stage
B)condenser
C)objective
D)ocular
E)nosepiece

Question 41

Which type of microscope does not use light in forming the specimen image?

A)bright-field
B)dark-field
C)phase-contrast
D)fluorescence
E)electron

Question 42

Who invented the first crude microscope by grinding glass?

A)Redi
B)Lister
C)Schultz and Schwann
D)Leeuwenhoek
E)Pasteur

Question 43

Basic dyes are

A)attracted to the acidic substances of bacterial cells.
B)anionic.
C)used in negative staining.
D)repelled by cells.
E)dyes such as India ink and nigrosin.

Question 44

The purpose of staining cells on a microscope slide is to

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

Question 45

Which type of microscope is the most widely used and shows cells against a bright background?

A)bright-field
B)dark-field
C)phase-contrast
D)fluorescence
E)electron

Question 46

The Gram staining procedure is best described as a/n __staining technique.

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

Question 47

Which type of microscope shows cells against a bright background and also shows intracellular structures of unstained cells based on their varying densities?

A)bright-field
B)dark-field
C)phase-contrast
D)differential interference
E)electron

Question 48

Which type of microscope cannot image live specimens?

A)bright-field
B)phase-contrast
C)dark-field
D)electron
E)differential interference

Question 49

A confocal scanning optical microscope

A)uses ultraviolet light to form a specimen image.
B)shows three-dimensional cell images from the cell surface to the middle of the cell.
C)produces specimen images on electron micrographs.
D)uses dyes that emit visible light when bombarded by ultraviolet rays.
E)requires specimens to be stained.

Question 50

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

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

Question 51

All of the following pertain to the fluorescence microscope except

A)uses electrons to produce a specimen image.
B)type of compound microscope.
C)requires the use of dyes like acridine and fluorescein.
D)commonly used to diagnose certain infections.
E)requires an ultraviolet radiation source.

Question 52

A confocal scanning optical microscope

A)uses a laser beam of light to form a specimen image.
B)shows only the surface of the specimen.
C)produces specimen images on electron micrographs.
D)uses dyes that emit visible light when bombarded by ultraviolet rays.
E)requires specimens to be stained.

Question 53

The specimen preparation that is best for viewing cell motility is

A)hanging drop.
B)fixed,stained smear.
C)Gram stain.
D)negative stain.
E)flagellar stain.

Question 54

A medium that is gel-like has less agar in it compared to a solid medium.

Question 55

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

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

Question 56

Some microbes are not capable of growing on artificial media.

Question 57

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

Question 58

Which type of media would be the best choice when shipping a sample of bacteria to a laboratory to be tested from a satellite office site?

A)transport
B)EMB
C)blood
D)thioglycollate

Question 59

What do the Gram stain,acid-fast stain,and endospore stain have in common?

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

Question 60

Which type of microscope achieves the greatest resolution and highest magnification?

A)bright-field
B)dark-field
C)phase-contrast
D)fluorescence
E)electron

Question 61

Mixed cultures are also referred to as contaminated cultures.

Question 62

At the end of the Gram stain,gram-positive bacteria will be seen as pink cells.

Question 63

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.In order to culture this pathogenic bacterium,one should use:

A)enrichment media.
B)selective media.
C)refrigeration temperature for incubation.
D)liquid media.

Question 64

One colony typically develops from the growth of several parent bacterial cells.

Question 65

Robert Koch and his lab workers first used agar in bacteriological media.Why did they find this media so much better than previous materials used to grow bacteria?

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

Question 66

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

Question 67

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

Question 68

Eosin-methylene blue agar,or EMB,is a commonly used bacteriological medium in a lab,used to grow gram-negative bacteria.There are two dyes in it,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 reduces the growth of most gram-positive bacteria.If an organism uses lactose,acid will be produced changing the pH of the medium and subsequently causing the bacterial colonies to change color.
Based upon this description,this medium is:

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

Question 69

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

Question 70

Normal incubation temperatures range from 30 ^$\circ$ to 60 ^$\circ$ C.

Question 71

When comparing the uses and benefits of the transmission electron microscope to the scanning electron microscope,you could say that:

A)the transmission EM has to be used with dyes.
B)the transmission EM is for external architecture of cells.
C)the transmission EM is used for internal inspection of cells and subcellular structures.
D)the transmission EM can be used with bacteria but not with viruses.

Question 72

Fixed smears of specimens are required in order to perform the Gram stain and endospore stain on the specimens.

Question 73

The real image is the reverse of the actual specimen.

Question 74

Let us say that the 100X magnification lens of your microscope has a resolving power of 0.15 microns (micrometers).The specimen that you will be looking at has bacterial cocci the size of 0.1 microns in diameter.Which statement is correct?

A)The cocci will be easily seen and very clear.
B)The cocci will be fuzzy-looking and blend together.
C)The cocci will appear much smaller than they really are because of the small resolving power.
D)The cocci will be totally invisible.

Question 75

Bacterial cultures are easily identified from their microscopic appearance.