microscopy

Question 1

how do you work out microscopy

Answer 1

image size/actual size

Question 2

light microscopes

Answer 2

• they use light to form an image
• maximum resolution is 0.2 micrometres
• maximum magnification is x1500

Question 3

pros and cons of a light microscope

Answer 3

pros:
easy to use
cheaper then electron
specimen does not have to be dead

cons:
low resolution and magnification
can only really see mitochondria and nucleus

Question 4

how does a TEM work

Answer 4

a beam of electrons is transmitted through the specimen, the more denser parts will absorb more electrons resulting in darker areas

Question 5

pros and cons of TEM

Answer 5

pros:
gives a high resolution
can see small structures

cons:
specimen must be thin
specimen must be dead
expensive
harder to use

Question 6

how does SEM work

Answer 6

specimen is scanned with a beam of electrons and the ones which get knocked off will gather to form the image

Question 7

pros and cons of SEM

Answer 7

pros:
shows surface of cell or can be 3D
thick sample can be used

cons:
not as high resolution as TEM
specimen must be dead