(5)

Question 1

produces an image made from light that is transmitted through a specimen

Answer 1

bright-field

Question 2

a special condenser is used so only the light reflected off the specimen enters the objective; appearance is of a brightly lit specimen against a dark background; often with better resolution than of the bright-field microscope

Answer 2

dark-field

Question 3

uses a fluorescent dye that emits fluorescence when illuminated with ultraviolet radiation.

Answer 3

fluorescence

Question 4

uses special optical components to exploit subtle differences in the refractive indices of water and cytoplasmic components to produce contrast; contrast is provided by differences in light intensity that result from differences in refractive indices in parts of the specimen that put light waves more or less out of phase; specimen appears as various shades of “darks” against a bright background.

Answer 4

phase contrast

Question 5

How is total magnification determined?

Answer 5

Total
Magnification
=
Magnification by the
Objective Lens
x
Magnification by the
Ocular Lens

Question 6

Understand how depth of field and field of view changes with magnification.

Answer 6

There is an inverse relationship between magnification and the depth of focus (field); the lower the power, the larger the depth of focus. As the power increases, the depth of focus (field) and field size decreases.

Question 7

supports the body tube & connects it to the base

Answer 7

arm

Question 8

a hollow tube that connects the ocular to the objective lenses through which light travels

Answer 8

Body tube

Question 9

the flat platform where you place your slides.

Answer 9

Stage

Question 10

using two knobs you can move the slide around

Answer 10

Mechanical stage

Question 11

hold the slide in place

Answer 11

Stage clips

Question 12

holds the objective lenses and can be rotated to change power

Answer 12

Revolving nosepiece

Question 13

the objective lens gathers light from the specimen, magnifies the image and projects it into the body tube.

Answer 13

Objective lenses

Question 14

a lamp that you turn on or off

Answer 14

Light source

Question 15

controls the amount of light entering the lens system

Answer 15

Diaphragm or Iris diaphragm

Question 16

used to change the contrast of the specimen viewed

Answer 16

Condenser

Question 17

produces large movements of the stage up and down to focus the specimen

Answer 17

Course Adjustment Knob

Question 18

used to bring the specimen into sharp focus under low power lenses and for all focusing under high power lenses.

Answer 18

Fine Adjustment Knob