Microscopy

Question 1

How do you calculate magnification?

Answer 1

Magnification = Image / Real object

I and R need to have the same units

Question 2

Define magnification

Answer 2

This tells you how many times bigger the image is than in real life

Question 3

Define resolution

Answer 3

The ability to see two structures very close together as separate structures

Question 4

What labels should you know on a light microscope? (Top to bottom)

Answer 4

• Eyepiece lens
• Objective lens
• Stage
• Mirror/ Light source

Question 5

How does the light microscope work?

Answer 5

• Examined using light
• Beam oases through specimen and lenses
• Thin sections so light can pass through

Question 6

What are the disadvantages of a light microscope?

Answer 6

• Objects can’t be living
• Objects need to be stained- which kills them
• Magnification only goes up to x1500
• Resolution isn’t always very good

Question 7

What are the advantages of a light microscope?

Answer 7

• Cheap to purchase
• Small and portable
• Vacuum not required

Question 8

What are the advantages of an electron microscope?

Answer 8

• High magnification (x500,000+)
• High resolution
• 3D image

Question 9

What are the disadvantages of an electron microscope?

Answer 9

• Expensive (£1,000,000)
• Lengthy and complex preparation
• Vacuum required
• Dead samples

Question 10

Fractions of a metre (including millimetre, micrometer and nanometre)

Answer 10

1 millimetre = 10^-3 m
1 micrometre = 10^-6 m
1 nanometre = 10^-9 m

Question 11

Why should the sample be thin?

Answer 11

• So that there is a single layer of cells

- So that light can pass through