OCR GCSE Combined Science A · J250
Specification B1.1c · Biology Paper 1
Revise: Electron Microscopy and Sub-cellular UnderstandingA transmission electron microscope, or TEM, passes a beam of electrons through a thin specimen. Different parts of the specimen transmit different amounts of the beam, creating an image that shows internal structures. A TEM produces a two-dimensional image of a thin section, rather than a view of the whole intact cell.