Microscopy

Question 1

Light microscope

Answer 1

• Relatively cheap
• Easy to use
• Rely on light
• Any details less than 0.2pm will apear blury
• Small so easy to transport

Question 2

Disadvantages of light microscope

Answer 2

Light microscope rely on light
Light has a much longer wavelength than electrons which means they have lower resolution than electron microscope
Meaning light microscopes have a lower maximum magnifucation

Question 3

Electron microscope

Answer 3

• Very expensive
• Hard to use (used by scientists in labs)
• Use electrons instead of light
• maximum resolution is 0.1nm
• (2000 x better than light microscope)
• You can use them to study sub cellular structures
• Can only view dead specimen

Greater resoloution and magnification

Question 4

Why do electron microscopes have greater magnification?

Answer 4

They use a beam of electrons rather than light waves, and the electrons have a shorter wavelength than light waves.

Question 5

Resolution

Answer 5

Resolution means how well a microscope distinguishes between two points that are close together.
A higher resolution means that the image can be seen more clearly and more detail

Question 6

What is magnification?

Answer 6

How many times larger the image appears compared to the real object.

Question 7

Why do we add stain ?

Answer 7

If your specimen is completely transparent or colourless it’ll make it easier to see (different stains highlight different structures within cells)

Question 8

Why do we add water on slide?

Answer 8

To secure the specimen in place

Question 9

Equation of total magnification

Answer 9

total magnification = eye piece lens magnification x objective lens magnification

Question 10

Equation for magnification

Answer 10

image size ÷ real size

Question 11

What sub-cellular structures are visible through microscope

Answer 11

Ribosomes, Cell membrane, Xylem cells

Question 12

What is the magnifiying power of an electron microscope?

Answer 12

2,000,000