Chapter 3

Question 1

gram staining: gram positive

Answer 1

purple

Question 2

gram staining: gram negative

Answer 2

red

Question 3

acid-fast staining

Answer 3

bacteria appears pink

Question 4

nonacid-fast staining

Answer 4

bacteria appears blue

Question 5

Streak Plate Method

Answer 5

small droplet is spread with an inoculation loop

most often used

Question 6

Pour Plate Technique

Answer 6

sample is inoculated into a cool agar to dilute the number of cells in each successive tube

Question 7

Spread Plate Technique

Answer 7

small volume of liquid from a diluted sample is pipetted onto medium and spread

Question 8

what are the different types of media?

Answer 8

physical state
chemical compound
functional type

Question 9

physical state: liquid media

Answer 9

water based solution that doesn’t solidify and flows freely

i. e. broth, milk, infusions (dissolving various solutes in distilled water)
- growth appears as dispersed, cloudy, or flaky

Question 10

physical state: semisolid media

Answer 10

contains solidifying agent (agar/gelatin) that thickens the media but does not produce a firm substrate

• used to determine the motility of bacteria, localize a reaction at a specific site
• needle is used to puncture the media to see growth patterns

Question 11

physical state: solid media

Answer 11

firm surface where cells can form discrete colonies

• good for culturing bacteria and fungi
• types: liqufiable (contains a solidifying agent that can melt) and nonliquifiable (doesn’t melt)

Question 12

chemical composition: chemically defined

Answer 12

synthetic

• contains pure chemical nutrients
• standardized/reproducible

Question 13

chemical composition: not chemically defined

Answer 13

non-synthetic

- no exact chemical formula, derived from animal or plan products

Question 14

functional type: general-purpose media

Answer 14

used to grow a broad spectrum of microbes

nonsynthetic media

Question 15

functional type: enriched media

Answer 15

complex organic substances (blood, serum, hemoglobin, growth factors)
fastidious bacteria: require growth factors and complex nutrients
often used for pathogens

Question 16

functional type: selective media

Answer 16

contains 1+ agents that prevent growth of specific microbes

used for isolating specific microbes from contaminated samples

Question 17

functional type: differential media

Answer 17

grows several types of organisms and allows one to see differences between them

Question 18

functional type: reducing media

Answer 18

absorbs oxygen reducing its availability to microbes
anaerobic microbes
as sugars for fermentation, pH indicator

Question 19

functional type: transport media

Answer 19

maintain and preserve specimens for clinical analyze

contains buffers and absorbents

Question 20

functional type: assay media

Answer 20

test effectiveness of antimicrobial drugs

Question 21

functional type: animal inculcation

Answer 21

used for microbes that only grow on living cells (obligate parasites)
used to determine effectiveness of drugs and vaccines
important source of antibodies, antisera, antitoxins, immune products