Midterm

Question 1

Culture medium

Answer 1

contains nutrients (C or N), required for cells to grow

Question 2

Complex medium

Answer 2

composed of digests of chemically undefined substances such as yeast and meat extracts or digests

Question 3

Defined medium

Answer 3

one for which precise chemical composition is known

Question 4

broth

Answer 4

a culture medium prepared as a liquid

Question 5

what does a solid medium usually contain?

Answer 5

agar

Question 6

what are deeps?

Answer 6

test tubes containing solid medium, which has been allowed to solidify in an upright position; usually for anaerobic growth

Question 7

slants

Answer 7

test tubes containing solid medium, solidifies at an angle and the surface of the agar is used for the maintenance of stock cultures of microorganisms

Question 8

selective medium

Answer 8

a nutrient medium designed to favor the growth of certain microbes and to inhibit undesirable competitors

Question 9

differential medium

Answer 9

provides a visible indication of a physiological charactristic of a microorganism

Question 10

PEA

Answer 10

phynl ethyl alcohol agar (selective only)

Question 11

MSA

Answer 11

mannitol salt agar (selective and differential)

Question 12

EMB

Answer 12

eosin methylene blue agar (selective and differential)

Question 13

sterilization

Answer 13

killing or removal of all living organisms and their viruses from a growth medium

Question 14

autoclave

Answer 14

sealed device that allows the entrance of steam under pressure

Question 15

what is the autoclave heated to?

Answer 15

121ºC at 15 pounds per square inch (psi) pressure for 15 minutes - 1 hour

Question 16

dry heat sterilization

Answer 16

kills by oxidation effects

Question 17

flaming

Answer 17

using bunsen burner

Question 18

hot-air sterilization

Answer 18

sterilized items are placed in an oven heated to 170ºC for 2 hours

Question 19

filtration

Answer 19

(heat sensitive liquids or gases)

Question 20

what is used to sterilize petri dishes?

Answer 20

gas chemosterilizers (like ethylene oxide)

Question 21

electromagnetic radiation

Answer 21

includes microwaves, ultraviolet radiation, x-rays, gamma rays, electrons

Question 22

practical uses for culturing microorganisms from the environment

Answer 22

knowledge of where microbes can be found help us to begin to resolve how they interact with each other and their microenvironment

Question 23

colony

Answer 23

a single cell will replicate and give rise to one

Question 24

contaminant

Answer 24

unwanted organisms which has been accidentally introduced into the culture

Question 25

hyphae

Answer 25

make mold colonies appear fuzzy due to branching and intertwined mass

Question 26

mycelium

Answer 26

vegetative part of the fungus

Question 27

does the amount and nutrients of a medium influence size, shape, and color of a colony?

Answer 27

yes