Microscopes

Question 1

What is resolution?

Answer 1

This is a measure of their ability to distinguish between two separate points.

Question 2

whats the magnification of light microscopes

Answer 2

1500 x

Question 3

Why do we stain specimens?

Answer 3

to make components more visible because many cells and tissue are colorless

cells and tissues are colorless

makes is easier to see and distinguish

Question 4

What are the rules for scientific drawing ?

1- Include a _____ of what the specimen is

2-State the _______ of the drawing

3-Use a sharp ______ on plain _______ paper

4-Draw smooth ______ lines (no sketch lines)

5-Do no ________

6-Clearly ______ all
structures

7-Ensure ________ are correct

Label lines should be draw with a ______, should not cross and have no __________

Answer 4

1-title

2-magnification

3- pencil , white

4-continuous

5-shade

6-label

7-proportions

8-ruler , heads

Question 5

What are the two types of electron microscopes?

Answer 5

Transmission electron microscope (TEM)

Scanning electron microscopes (SEM):

Question 6

Why cant electron microscopes see in color?

Answer 6

unlike light microscopes, there is only one wavelength transmitting (electrons)

Question 7

MAHRAN LOOK AT POWERPOINTS AND LOOK AT PICTURES

Answer 7

MAHRAN LOOK AT POWERPOINTS AND LOOK AT PICTURES

Question 8

How does a light Microscope work?

Answer 8

using a beam, The light passes through the specimen and is focused through a lens which shows you a magnified image

Question 9

What can’t light microscopes resolve?

Answer 9

two points that are closer than half a wavelength of visible light

Question 10

What are the features of a Transmission electron microscope?

Answer 10

Electrons pass through and around the specimen, giving some contrast - the image is 2D with a magnification of x500,000

Question 11

What are the features of a Scanning electron microscope?

Answer 11

Electron do not go through or pass around the sample but reflect off – the image is 3D with a magnification of x100,000

Question 12

What Advantages of electron microscopes?

Answer 12

The Resolution is 0.2nm (1000x more than a light microscope)

We can see structured detailed images of organelles inside the cells

The SEM produces 3D images that can uncover details of contorts and cellular tissue arrangement – not possible with Microscopes

Question 13

What are the disadvantages of an electron microscope?

Answer 13

Electron beams are deflected by air molecules so the sample has to be in a vacuum – so the sample has to be dead

Electron microscopes of very expensive (min of - £250,000)

Preparing slides and samples for electron microscopes requires a high level of training and skill – as the slides have to be very thin