LAB 2 - The Microscope

Question 1

What are the 2 types of microscopes?

Answer 1

1. Dissecting microscope (stereoscope)

2. Compound light microscope

Question 2

What is a dissecting microscope used for?

Answer 2

-to view larger (or opaque) organisms

Question 3

What is the magnification of a dissecting scope?

Answer 3

-low mag. (8x-35x)

Question 4

Is a dissecting scope mono or binocular?

Answer 4

both

Question 5

What is a compound light microscope used for?

Answer 5

-to magnify a very small object

Question 6

What is the magnification of a compound light scope?

Answer 6

40x-1000x

Question 7

Is a compound scope mono or binocular?

Answer 7

both

Question 8

What is used to clean a microscope?

Answer 8

special lens cleaning paper only

Question 9

What are the 4 magnification objects and their names?

Answer 9

1. 4x scanning (40x)
2. 10x low-power (100x)
3. 40x high power (400x)
4. 100x oil-immersion (1000x)

Question 10

What mag. do you start with?

Answer 10

4x

Question 11

What are the 2 types of slides?

Answer 11

1. prepared (permanent)

2. wet-mount (temporary)

Question 12

What is focusing a microscope?

Answer 12

• increasing/decreasing distance between specimen on slide

- increasing/decreasing objective lens

Question 13

As magnification increases, the diameter of the field becomes ________

Answer 13

smaller

Question 14

What is the equation for diameter of field of view?

Answer 14

D(a) x Mag(a) = D(b) x Mag(b)

Question 15

What is the approximate Diameter of Field of View for each objective?

Answer 15

4x 4.0mm
10x 2.0mm
40x .4mm
100x .2mm

Question 16

As magnification increases the depth of field _______

Answer 16

decreases

Question 17

Which objective has the greatest depth of field?

Answer 17

scanning power

Question 18

In lab, which slide was used to test depth of field?

Answer 18

different colored strings

Question 19

What organism was used to practice focusing?

Answer 19

Daphnia (water flea)

Question 20

What are the 3 major parts of a microscope?

Answer 20

1. lens system
2. adjustable light source
3. focusing mechanism

Question 21

What is the condenser?

Answer 21

focuses the light on the specimen

Question 22

What is the iris diaphragm?

Answer 22

• built into condenser

- allows you to regulate light intensity

Question 23

Wha is the light pathway?

Answer 23

• passes through sample, enters objective lens

- passes through o cular lens (eyepiece)

Question 24

monocular vs. binocular

Answer 24

Monocular: singular ocular lens on rotating head
Binocular: 2 ocular lenses, moved together or apart

Question 25

What is magnification?

Answer 25

indicates number of times the image of the sample is enlarged by microscope

Question 26

What is resolution?

Answer 26

- ability to clearly distinguish objects which are close together - expressed as distance (nm or micrometer)

Question 27

What is blue light?

Answer 27

-utilized by microscopes because of short wavelength to increase resolution

Question 28

Resolving power ______ as the wavelength of light used decreases

Answer 28

increases

Question 29

What is working distance?

Answer 29

distance between the objective and the sample

Question 30

What do parcentric and parfocal mean?

Answer 30

-when new lens is rotated in place, the image remains centered + close to focus

Question 31

What is field of view?

Answer 31

diameter of visible image

Question 32

What is depth of field?

Answer 32

distance between the highest and lowest points in the sample that are simultaneously in focus

Question 33

What 3 things decrease with increasing mag.?

Answer 33

1. depth of field 2. field of view 3. light intensity