(a) Who coined the term 'cell' ?
(b) Name three major differences between light microscope and electron microscope.
(c) Give important points of modern cell theory.

Explanation

(a) Robert Hoole coined the term cell.
(b) `{:("Light Microscope","Electron Microscope"),("1. Internal vacuum is not present.","1. Internal vacuum is essential."),("2. It uses glass lenses.","2. It uses electromagnets."),("3. It uses beam of light to illuminate the object.","3. It uses beam of electrons instead of light."):}`
(c) Modern cell theory postules that
(i) All living organisms are composed of cells.
(ii) A cell is a mass of protoplasm containing a nucleus and bounded by a cell membrane, and in many cases by a cell wall also.
(iii) All cells are basically alike in structure and metabolic activities.
(iv) The functions of an organism as a whole is the result of the activites and interactions of the constituent cells.
(v) All living cells arise from the pre-existing cells.