microscopy

Question 1

what is magnification?

Answer 1

making things look larger

Question 2

what is resolution?

Answer 2

distinguishing between two objects close together

Question 3

give the units of the following:
millimetre
micrometre
nanometre

Answer 3

mm
backwards Um = 1/1000 mm
nm= 1/100000 mm

Question 4

what are the wavelengths of the 3 types of microscope?

Answer 4

400-700nm, 0.005nm, 0.005nm

Question 5

what are the lenses for each microscope?

Answer 5

glass, electromagnetic, electromagnetic

Question 6

what specimen can be tested on the types of microscope?

Answer 6

cellular components & cell type, non living and non living

Question 7

what are the maximum resolutions for the microscopes?

Answer 7

200nm, 1nm, 1nm

Question 8

what image is given for each?

Answer 8

colour, monochrome and monochrome

Question 9

max magnifiaction

Answer 9

1500x, 250000x, 10000x

Question 10

staining

Answer 10

diferential, heavy metal, carbon or gold

Question 11

give 4 advantages of using a light microscope

Answer 11

colour, non living and living, lots of different stains and diferential staining for identification of cellular components

Question 12

give 1 disadvantage of a light microscope

Answer 12

max resolution is 200nm

Question 13

give advantages of using TEM

Answer 13

view very thin material, large magnification,detailed, electromagnetic lenses

Question 14

disadvantages of TEM

Answer 14

non living only, low resolution, monochrome image, expensive, samples must be stained with heavy metals

Question 15

advantages of SEM

Answer 15

max resolution 10000x, detailed

Question 16

disadvatnges of SEM

Answer 16

low resolution, black & white image only, expensive, samples must be stained with carbon or gold, non living only

Question 17

describe a laser scanning confocal microscope

Answer 17

optical sectioning, image re- constructed with computer allowing 3D reconstruction of complex objects, sees images one depth level at a time, interior imaging is greatly enhanced over simple microscopy

Question 18

what is the formula for calculating the magnification of an image

Answer 18

magnification= image size/object size

Question 19

why do you need to stain an object before viewing it in a microscope?

Answer 19

sometimes the object is transparent so staining solves this as some of the stain is taken up by some parts of the object than others- the contrast makes the different parts show up

Question 20

what is the staining technique for electron microscopes?

Answer 20

samples dipped in heavy metal, the metal ions scatter the electrons creating a contrast