Microscopy/Microscopy techniques

Question 1

What do microscopes do?

Answer 1

They let us see things we cant see with the naked eye.

Question 2

What are the two types of microscopes?

Answer 2

LIGHT MICROSCOPES
ELECTRON MICROSCOPES

Question 3

How does a light microscope work?

Answer 3

Use light and lenses to form an image of a specimen and magnify it.

Question 4

What do light microscopes let us see?

Answer 4

They let us see individual cells and large sub cellular structures like nucleus, cell walls, chloroplasts etc.

Question 5

How do electron microscopes work?

Answer 5

Electron microscopes use electrons instead of light to form an image. They have a much HIGHER MAGNIFICATION than light microscopes. They also have a much HIGHER RESOLUTION.

Question 6

What is resolution?

Answer 6

The ability to distinguish between two points so a higher resolution gives a sharper image.

Question 7

What do electron microscopes see?

Answer 7

These can see the internal structures of things such as mitochondria, chloroplasts, ribosomes and plasmids.

Question 8

word equation for magnification?

Answer 8

Magnification= Image size
——————
Resolution

Question 9

How to prepare a microscope slide?

Answer 9

1) Add a drop of water t the middle of the slide
2)Cut out an onion and separate out into layers use tweezers to peel off some epidermal tissue from bottom layer.
3)Add a drop of stain
4)Add a drip of stain(iodine solution)to tissue. Stain highlights objects in a cell by adding colour to them.
5)Place a coverslip(a square thin, transparent plastic glass.

Question 10

How to work out magnification using cell drawing

Answer 10

Magnification=Length of drawing of the cell

Question 11

How to use microscope?

Answer 11

1)Clip the slide and stage
2)Select the lowest powered objective lens
3)Use the coarse knob to move it
4)When the objective lens almost touches the slide we stop turning the dial
5)Look down through the eyepiece and slowly turn the coarse focussing dial
6)Do this until the cells come into focus
7)Use the fine focussing dial to bring the cells into a clear focus

Question 12

reminder to be able to label a microscope

Question 13

What does the image equal?

Answer 13

Image= Magnification x Real size

Question 14

Describe the purpose of adjustment knobs.

Answer 14

To adjust the focus so you move the stage closer or further away from uour target

Question 15

A teacher has viewed the cells
She wants to produce a drawing of them
Give to way in which she can unsure she produces an accurate and useful drawing.

Answer 15

1) Use a sharp pencil
2) No shading or colouring

Question 16

How many micrometres in one millimetre?

Answer 16

1000

Question 17

Why is a mirror used instead a bulb sometimes?

Answer 17

It can be used to reflect light up through the microscope slide.

Question 18

What are the three different objective lenses magnification?

Answer 18

1) 4x
2) 10x
3) 40x

Question 19

What are the two types of focusing dials?

Answer 19

1)COARSE
2)FINE

Question 20

What does the coarse focussing dial do

Answer 20

Increases the distance between the objective lens and the slide.

Question 21

To calculate the total magnification when using a microscope you:

Answer 21

We multiply the magnification of the eyepiece lens by the magnification of the objective lens.