Answer:

Cell Before microscopes were first used in the seventeenth century, no one knew for certain that living organisms were composed of cells. The first microscopes were light microscopes. A light microscope (LM) works by passing visible light through a specimen, such as microorganism or a piece of animal or plant tissue. Knowledge in cell structure took a giant leap forward as biologists began using the electron microscope in 1950s. Instead of light, the electron microscope (EM) uses a beam of electrons. The EM has a much higher resolving power than the light microscope. In fact, the most powerful moderns EMs can distinguish objects as small as 0.2 nanometer (nm), which is the size of a large atom. Cells, cellular organelles and even molecules like DNA and protein are much larger than single atoms. Biologists use the scanning electron microscopes (SEM) to study the detailed architecture of cell surfaces. The SEM uses an electron beam to scan the surface of a cell or group of cells that have been coated with metal. The metal stops the beam from going through the cells. When the metal is hit by the beam, it emits electrons. The electrons are focused to form an image of the outside of the cells. The transmission electron microscope (TEM) is used to study details of internal cell structure. The TEM uses electromagnets as lenses, as do all electron microscopes. The electromagnets bend the electron beam to magnify and focus an image onto a viewing screen or photograph film. Guide question 1. Which type of microscope would you use to study: a. changes in the shape of a living human white blood cell ________________ b. the finest details of surface texture of a human hair _________________ c. detailed structure of an organelle in a human liver cel

Answers

mag isip ka pre wag puro ml

Explanation:

mag isip wag puro ml