Topic 3A.1 Observing Cells

light microscope (optical microscope)

a tool that uses a beam of light and optical lenses to magnify specimens up to 1500 times life size

magnification

a measure of how much bigger the image you see is than the real object

electron microscope

a tool that uses a beam of electrons and magnetic lenses to magnify specimens up to 500000 times life size

resolution (resolving power)

a measure of how close together two objects must be before they are seen as one

artefacts

things observed in a scientific investigation that are not naturally present; they occur as a result of the preparation or investigation

graticule

a series of lines in the eyepiece of a microscope which help you measure specimens accurately

transmission electron micrographs (TEMs)

micrographs produced by the electron microscope that give 2D images like those from a light microscope, but magnified up to 500000 times

scanning electron micrographs (SEMs)

micrographs produced by the electron microscope that have a lower magnification than TEMs, but produce a 3D image