microscopy

Question 1

methods of studying cells

Answer 1

light/optical microscopes
electron microscopes

Question 2

light microscopes

Answer 2

uses light/lenses limited to 1500x magnification
long wavelength of light rays, 0.2 micrometres resolutions

Question 3

scanning electron microscopes

Answer 3

exposes a specimen to electrons rather than light
2x10^6 magnification
shorter wavelength of 0.1nm
3D, used to view whole tissue/cell

Question 4

Transmission electron microscopes

Answer 4

uses electrons
2x10^6 magnification
0.1nm resolution
2D only, views sections of cells/tissues

Question 5

process of using TEM and SEM

Answer 5

Scanning electron microscopes
~ specimens coated with a thin layer of metal (gold, platinum etc.)
electrons reflected from the surface of the specimen, producing a 3D image

Transmission electron microscopes
~ Very thin slices made, stained with heavy metals
electrons do not pass through heavily stained parts, because they are absorbed inside cells

Question 6

calibrating a microscope

Answer 6

use eyepiece graticule, 1mm to 100m
use a scale

Question 7

calculations

Answer 7

image size/magnification = actual size