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History OF CELL BIOLOGY AND PARTS OF A MICROSCOPE ANITHA VIJAYAN B.Ed STUDENT OBJECTIVES HISTORY OF CELL BIOLOGY MICROSCOPE PARTS OF A MICROSCOPE REFERENCE TO understand the history of cell biology. To understand the contributions of scientists in the field of cell biology . To study about microscope. To study the different parts of a microscope. 1485 - da vinci invented the use of lenses. 1595 – Jansen invented the 1st compound microscope. 1655 – Robert Hooke described “Cells” in cork. 1674 – Leeuwenhoek discovered protozoa. 1833 –Robert Brown described Cell Nucleus in orchid. 1838-1839 – Schleiden and Schwann proposed the Cell Theory. 1840 – Albrecht von Roelliker found out that sperms and eggs are also cells. 1856 – N.Pringsheim found out how sperms penetrates into egg. 1858 – Rodolf Virchow find out that Cells comes only from pre-existing cells. 1857 – Kolliker described Mitochondria. 1879 – Flemming described the chromosome behavior during mitosis. 1883 – Bovery and Sutton described the Chromosome theory of heredity. 1898 – Golgi described the Golgi apparatus. 1938 - Behren used differential centrifugation to separate nuclei from cytoplasm. 1939 – Siemens produced the first transmission electron microscope. 1952 – Gey and coworkers establish the continues human cell line. 1955 – Eagle defined the nutritional needs of the animal cell in culture. 1965 – Ham introduce a defined serum free medium. 1965 – Cambridge Instruments produced the first commercial scanning electron microscope. 1976 – Sato and colleagues published the papers showing that different cell lines require different mixtures of hormones and growth factors in serum free media. 1981 – Transgenic mice and fruit flies were produced. Mouse embryonic stem cell line established. 1998 – Mice were cloned from somatic cells. Microscopes are used to see objects that are invisible to knacked eye. Magnification and resolving power determines the quality of the microscope. Magnification – Magnification of the eye piece and objective. Resolving power – Ability to reveal closely adjacent structural details. Two forms of microscopes-Monocular And Binocular. EYE PIECE OBJECTIVE BODY TUBE STAGE ARM IRIS DIAPHRAM COURSEADJESTMENTS CONDENSER FINE ADJESTMENTS MIRROR NOSE PIECE BASE MICROSCOPE EYE PIECE Composed of two plano convex lenses. Different magnifications – 5x,10x,15x,20x Lesser magnification gives sharper images. BODY TUBE It is a cylindrical tube Upper end- Eye piece; Lower end –Nose piece Up and Down movement helps in focusing. ARM Supports the body tube. Helps to carry the microscope in hand. It gives correct height and angulation to the body tube. COURSE ADJESTMENT Moves the body tube up and down ,inorder to find the perfect position to focus the specimen. It can be used only in low power objective. FINE ADJUSTMENT Used to achieve the fine focus of a specimen. Moves the body tube up and down ,inorder to find the perfect position. Used at both low power and high power objective. NOSE PIECE This is the revolving mouth Objectives of varying focal length are screwed here OBJECTIVE Objective lenses are fitted to nose piece. Each objective has more than one plano convex lenses. STAGE It is a platform., which admits light from the mirror. It have a pair of clips that holds the slides. Regulate the light. It is controlled by a lever . IRIS DIAPHRAGM CONDENSER It s a lens located above the diaphragm. Its position can be controlled by knob. It is situated below the stage. It has a concave and flat surface. It reflects light through diaphragm to the condenser MIRROR BASE It gives a firm steady support. https://www.google.co.in/search?q=cells&biw=1366&bih=667&es_ sm=93&source=lnms&tbm=isch&sa=X&ved=0CAYQ_AUoAWoVChMI nIbi44-VyQIVwj6OCh1O0QLZ#imgrc=YirpsTJrNPmMCM%3A