OCR A-level Biology: Module 2 | 156 Questions with 100% correct Answers | Verified

Light microscope - An instrument that uses visible light and glass lenses to enable the user to objects magnified many times Compound light microscope - A light microscope which uses two lenses to magnify an object; the objective lens, which is placed near to the specimen and an eyepiece lens, through which the specimen is viewed Differential staining - Using specific stains to distinguish different types of cell Counterstain - Application of second stain with a contrasting colour to sample for microscopy Electron microscopy - Microscopy using a microscope that employs a beam of electrons to illuminate the specimen. As electrons have a much smaller wavelength than light they produce images with higher resolutions than light microscopes Ultrastructure - The ultrastructure of a cell is those features which can be seen by using an electron microscope Artefacts - Objects or structures seen through a microscope that have been created during the processing of the specimen Transmission electron microscope - An electron microscope in which a beam of electrons is transmitted through a specimen and focused to produce an image Scanning electron microscope - An electron microscope in which a beam of electrons is sent across the surface of a specimen and the reflected electrons are focused to produce a three-dimensional image of the specimen surface Laser scanning confocal microscope - A microscope that employs a beam of fluorescence and a pinhole aperture to produce an image with a very high resolution