lab four

Question 1

light microscope

Answer 1

coordinated system of lenses arranged to produce an enlarged, focusable image of a specimen

Question 2

magnification

Answer 2

increase in apparent size, accompanied with resolution

Question 3

resolution

Answer 3

ability to distinguish 2 points as separate points

Question 4

ocular eyepiece

Answer 4

uppermost lens/series of lenses, most have magnification of 10X

Question 5

ocular tube

Answer 5

connects ocular to body tube

Question 6

scanning objective lens

Answer 6

4x magnification, larger specimens

Question 7

low-power objective lens

Answer 7

10x magnification, coarse/preliminary focusing

Question 8

high-power objective

Answer 8

final/fine focusing, 40x magnification

Question 9

oil-immersion objective lens

Answer 9

oil immersion helps magnify specimen, 100x magnification

Question 10

mechanical stage

Answer 10

platform where slides are placed to accurately control movement of slides

Question 11

stage clips

Answer 11

secure slide

Question 12

coarse adjustment knob

Answer 12

adjusts microscope on 4x and 10x only

Question 13

fine adjustment knob

Answer 13

adjusts specimen into final focus

Question 14

condenser lens

Answer 14

lens system found beneath stage that focuses light

Question 15

iris diaphragm

Answer 15

regulates light entering microscope

Question 16

always start examination with…

Answer 16

low-power objective

Question 17

magnification equation

Answer 17

product of power of ocular and power of objective

Question 18

what does resolving power depend on

Answer 18

design and quality of objective lenses

Question 19

depth of filed

Answer 19

thickness of the specimen in focus at any one time

Question 20

first microscope

Answer 20

used by Robert Hooke in 1665 to observe cork

Question 21

Anton van Leeuwenhoek

Answer 21

built simple microscope with one lens
- father of microscopy
- built over 240 microscopes
- first to see/describe microorganisms (tiny animalcules”

Question 22

compound light microscope

Answer 22

allows light to pass through specimen and uses two lenses
- magnification
- resolution

Question 23

parfocal

Answer 23

if one objective is in focus and a change is made to another objective, the focus will not be lost

Question 24

what happens to DOF as magnification increases

Answer 24

it gets thinner

Question 25

electron microscopes

Answer 25

• no light
• beam of electrons
• placed inside vacuum chamber so electrons don’t bounce off of gas molecules
• not used to view living cells

Question 26

2 type of electron microscopes

Answer 26

1. transmission
2. scanning

Question 27

transmission electron microscope

Answer 27

stream of electrons transmitted through thinly sliced specimen
- magnets guide stream of electrons
- image projected on photographic plate
- 200,000 magnification

Question 28

what is magnification usually accompanied with?

Answer 28

resolution

Question 29

contrast

Answer 29

the ability to discern detail and see difference between light/dark areas