Lesson 3

Question 1

methods of identifying microorganisms

Answer 1

living state and fixed state

Question 2

bacteria seems to be going in a definite direction

Answer 2

true motility

Question 3

bacteria are bouncing back and forth rapidly due to bombardment from molecules of water

Answer 3

brownian movement

Question 4

• a thin film of material containing the microorganisms is spread over the surface of the slide

Answer 4

smearing

Question 5

the slide is fixed by passing it through the flame of an alcohol lamp several times, smear side up

Answer 5

fixation

Question 6

coloring the microorganisms with a dye that emphasizes certain structures

Answer 6

staining

Question 7

are cationic meaning they are positively charged

Answer 7

basic dye

Question 8

are anionic meaning they are negatively charged

Answer 8

acidic dyes

Question 9

an aqueous or alcohol solution of a single basic dye

Answer 9

simple staining

Question 10

differential staining

Question 11

to tightly bind the primary stain to the bacterial cell wall

Answer 11

mordant

Question 12

developed in 1884 by the Danish bacteriologist

Answer 12

Gram Stain

Question 13

develops Gram Staining

Answer 13

Hans Christian Gram

Question 14

classifies bacteria into two large groups: gram-positive and gram-negative

Answer 14

Gram stain

Question 15

primary stain

Answer 15

crystal violet

Question 16

mordant

Answer 16

Gram’s iodine

Question 17

decolorizing agent

Answer 17

ethanol, acetone or a combination of both

Question 18

secondary stain

Answer 18

safranin