Explain7 marksChallenge
A student prepared a temporary mount of Bacillus subtilis cells and viewed them under a light microscope at a total magnification of ×400. She then obtained a transmission electron micrograph of the same bacterium at a magnification of ×20 000.
(a) Define the term magnification. (b) Define the term resolution. (c) Explain why the electron micrograph can reveal details such as the cell wall and plasma membrane as distinct structures, whereas the light microscope image shows only the general shape of the bacterium. (d) The student used an eyepiece graticule to measure the length of a bacterium in the light microscope. Describe how she would calibrate the eyepiece graticule using a stage micrometer.