Magnification and Quantitive Units

Question 1

Equation: Magnification

Answer 1

Image size
—————
Actual size

Question 2

What is magnification

Answer 2

The process of enlarging an image

Question 3

What is resolution?

Answer 3

The ability to distinguish between two points as separate structures (level of detail)

Question 4

What is a compound microscope?

Answer 4

A microscope that uses multiple lenses

Question 5

What is the maximum magnification of a light microscope?

Answer 5

x2000

Question 6

How do you calculated the overall magnification of a microscope?

Answer 6

Overall magnification = eyepiece magnification x objective magnification

Question 7

What is a light microscope?

Answer 7

A type of microscope that uses lenses to magnify an image

Question 8

What is an electron microscope?

Answer 8

A microscope that uses beams of electrons to form an image

Question 9

What are the differences between light and electron microscopes? (3)

Answer 9

• Light microscopes use light, electron microscopes use electrons
• Electron microscopes have a higher resolution
• Electron microscopes have a higher magnification

Question 10

How have changes in microscopes lead to us seeing things in the detail we do today?

Answer 10

• Compound microscopes was the first type invented
• Single lens microscopes then invented
• Optical quality of light microscopes increased over time but reached a point where magnification couldn’t get higher
• First electron microscope in 1931

Question 11

What are the disadvantages of electron microscopes?

Answer 11

• Living cells cannot be observed since they have to be placed in a vacuum
• Expensive

Question 12

What are the two types of electron microscopes?

Answer 12

• A Transmission Electron Microscope (TEM)
• A Scanning Electron Microscope (SEM)

Question 13

What is one mm in metres?

Answer 13

1x10^-3

Question 14

What is one μm in metres?

Answer 14

1x10^-6

Question 15

What is one nm in metres?

Answer 15

1x10^-9

Question 16

What is one pm in metres?

Answer 16

1x10^-12

Question 17

What is the stage on a microscope?

Answer 17

Where the slide is placed

Question 18

Where is a slide placed on a microscope?

Answer 18

On the stage

Question 19

What holds a slide in place on a microscope?

Answer 19

Stage clips

Question 20

What is used to shine light onto a microscope slide?

Answer 20

Either a lamp or a mirror

Question 21

What are the two types of microscope lens?

Answer 21

• Objective lens
• Eyepiece lens

Question 22

What are the names of the lenses above the stage on a microscope?

Answer 22

Objective lenses

Question 23

What are the two parts of the microscope that improve the resolution of the image?

Answer 23

• Coarse focussing wheel
• Fine focussing wheel

Question 24

What is the coarse focussing wheel on a microscope for?

Answer 24

Positioning the objective lens so it almost touches the slide

Question 25

What is the fine focussing wheel on a microscope for?

Answer 25

Adjusting the resolution of the image when viewing the slide through the eyepiece lens

Question 26

Describe the preparation of a microscope slide

Answer 26

- Put a drop of water on a microscope slide - Put the specimen on the water - Add a drop of a stain eg. iodine - Place coverslip on top