Microscopes

Question 1

What does magnification mean?

Answer 1

The degree to which the size of an image is larger than itself

Question 2

What is the resolution

Answer 2

The ability to distinguish between two points

Question 3

What are the three types of microscopes

Answer 3

Light
Laser scanning
Electron

Question 4

How does a laser scanning microscope work

Answer 4

Uses a laser to scan an object
Image is displayed on computer screen

Question 5

Advantages of a laser scanning microscope

Answer 5

High resolution and high contrast
Can focus at different depths
Multiple images can be combined to make a 3d image

Question 5

What are the two types of electron microscopes

Answer 5

Transmission electron microscope

Scanning electron microscope

Question 6

State 3 differences between TEM and SEM

Answer 6

TEM - electrons pass through specimen, SEM - electrons bounce off specimen

TEM image is 2D, SEM image is 3d

TEM has a higher magnification

Question 7

What is the resolution of a light microscope

Answer 7

200nm

Question 8

What is the resolution of an electron microscope

Answer 8

0.1nm

Question 9

What is sectioning

Answer 9

Thin sections of a specimen are cut so light can easily pass through it

Question 10

What is staining

Answer 10

Stains are used which bind to chemicals or structures in or on cells

This colours the specimen enabling it to be seen

Question 11

What is differential staining

Answer 11

Some stains bind to specific structures meaning these can be
differentiated from others

Question 12

Name two stains

Answer 12

Methylene blue
DNA red