Biol 1 - Microscopes Revision notes on microscopes, aqa AS biology unit one 2.0 / 5 based on 1 rating ? BiologyPractical applications of biologyASAQA Created by: StephanieCreated on: 12-05-12 14:45 Terms Magnification: how much bigger the image is then the specimen magnification = length of image / length of specimen Resolution: how detailed the image is - how well it distinguishes between two points 1 of 5 Light Microscopes Use Light Low resolution Low magnification 2 of 5 Electron Microscopes Uses electron to form an image Shorter wave length higher resolution higher magnification can't be use on live specimens 3 of 5 Transmission Electron Microscopes (TEM) Electromagnets used to focuz a beam of electrons on specimen Denser parts absorb more and appear darker (like xrays) Gives high resolution Can only be used on thin specimens Specimens have to be specially prepared in a vaccuum 4 of 5 Scanning Electron Microscopes (SEM) Scan a beam of electrons over sample knocks off electrons collected in a cathode ray tube to make image shows surface of specimen & can be 3D can be used on thick specimens lowere resolution than TEM 5 of 5
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