3

Question 1

Dark field microscopy

Answer 1

specimen is brightly illuminated on dark background

Question 2

depression slide

Answer 2

circular depression in middle

Question 3

hanging drop slide

Answer 3

specimen hangs suspended from an inverted coverslip mounted on a depression slide

Question 4

resting stage

Answer 4

the stage of the growth curve in which cells are metabolically inactive

Question 5

star diaphragm

Answer 5

metal diaphragm used for dark field microsooy. its opaque center deflects the light rays that converge on the objective so that only the oblique rays strike the specimen. net result is a dark colored field with brightly colored specimen

Question 6

vital stain

Answer 6

stain able to differentiate living from dead cells

Question 7

wet mount slide

Answer 7

drop containing the specimen is placed on the surface of a clean slide, followed by the addition of a coverslip over the drop.

Question 8

bright: dead cells vs living

Answer 8

blue, colorless

Question 9

Dark: dead vs living

Answer 9

dull, bright

Question 10

drawbacks of wet mounts

Answer 10

drying out quickly which cause false motility.
inability to see because it is not sufficiently different in refractive index from the suspended fluid (can be resolved by reducing light intensity)
not useful for observing thick preparations such as hay infusions

Question 11

Which organism did not move

Answer 11

Staph