Practical 2 - Calibration Of The Light Microscope At Low To High Power + Magnification Calculation O A Drawing

Question 1

Name 5 key parts of the microscope

Answer 1

-Focus wheels
-Objective lenses
-Slides
-Stage
-Eye piece

Question 2

What’s the name of the lenses on a microscope?

Answer 2

Objective lenses

Question 3

What do you look into on a microscope?

Answer 3

Eye piece

Question 4

What do you use to focus on a microscope?

Answer 4

Focus wheels

Question 5

What do we need to fit the eye piece with in this experiment?

Answer 5

An eye piece graticule

Question 6

What do we need for this experiment?

Answer 6

-Microscope fitted with eye piece graticule
-Stage micrometer
-Microscope slide + cover slip
-Paper towel

Question 7

What do we measure in on an eye piece graticule?

Answer 7

Eye piece units (epu)

Question 8

How many eye piece units are on an eye piece graticule?

Answer 8

100

Question 9

How do we calibrate a microscope?

Answer 9

Using a stage micrometer, you line its zero up with the eye piece graticule’s zero, ensuring they’re parallel.
Stage micrometer units divided by eye piece units = stage mm units
1 epu: answer x one stage mm unit
= answer in mm
(Can x1000 to get in micro metres)

Question 10

How do we measure the length of each division on the eye piece graticule at different magnifications?

Answer 10

Use a stage micrometer

Question 11

What are the two options of stage micrometers to use, and what is the value of 1 unit on each of these?

Answer 11

1mm (1 unit = 0.01mm)
10mm (1 unit = 0.1mm)

Question 12

What’s the method for this experiment?

Answer 12

1. Calibrate from low to high power
2. Take 1 human hair + water + cover with slip on the slide + press with paper towel
3. Measure the width of the hair in eye piece units + use calibration to calculate the actual size
4. Draw section of hair and use the method to calculate its magnification

Question 13

Magnification formula

Answer 13

i
——
a I m

(Triangle)

Question 14

What’s the magnification at low power on the microscope we used?

Answer 14

40x

Question 15

What’s the magnification at medium power on the microscope we used?

Answer 15

100x

Question 16

What’s the magnification on high power on the microscope we used?

Answer 16

400x

Question 17

What’s the calibration at low power (40x)?

Answer 17

0.025mm

Question 18

What’s the calibration at medium power (x100)?

Answer 18

0.01mm

Question 19

What’s the calibration at high power (400x)?

Answer 19

0.0025mm

Question 20

What does the calibration actually mean?

Answer 20

Every one of the eye piece units is this much

Question 21

How do we calculate the actual size of the hair?

Answer 21

Eye piece units x calibration at this size

Question 22

What do the 6 differences between the light and electron microscope cover?

Answer 22

Beam of ________
Wavelength of beam
Images
Specimens
Resolution power
Magnification

Question 23

Compare the beams between light and electron microscopes

Answer 23

Light - beam of light
Electron - beam of electrons

Question 24

Compare the wavelength of the beams from the light and electron microscopes

Answer 24

Light - longer wavelength
Electron - shorter wavelength

Question 25

Compare the images produced by the light and electron microscope

Answer 25

Light - colour
Electron - black and white only

Question 26

Compare the specimens that can be observed using a light and electron microscope

Answer 26

Light - can see live specimens
Electron - only dead specimens

Question 27

Compare the resolution powers in light and electron microscopes

Answer 27

Light has lower resolution than electron

Question 28

Compare the magnification between the light and electron microscopes

Answer 28

Light has lower magnification than electron

Question 29

What does the fact that the electron microscope has higher resolution and magnification mean?

Answer 29

We receive images that are much clearer and in greater detail

Question 30

Why is staining used?

Answer 30

To give a contrast between cell structures

Question 31

Can we use staining to observe live cells? Why?

Answer 31

No, as it kills them

Question 32

What is one unit of the 1mm stage micrometer?

Answer 32

0.01mm

Question 33

What is one unit of the 10mm stage micrometer?

Answer 33

0.1mm

Question 34

Magnification

Answer 34

How many times bigger the image is compared to the object

Question 35

How many times bigger the image is compared to the object

Answer 35

Magnification

Question 36

Resolving power

Answer 36

the minimum distance by which two points must be spectated in order for them to be seen as two distinct points other than a single focused image

Question 37

The minimum distance by which two points must be spectated in order for them to be seen as two distinct points other than a single focused image

Answer 37

Resolving power