This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Microbiology
Microscope used in microbiology - 
Select and explain. 
A. Light microscope, B. Phase contrast microscope, C. Fluoroscent microscope, D. All
D: All
Answer: D: All 
Explanation: Ans. is 'd' i.e., All Why is it necessary to use microscope in microbiology? The diameter of the smallest object that can be seen by naked ( unaided) eye is about 200U. Most microorganisms are smaller than this and therefore, they should be sufficiently magnified before study. For this purpose various types of microscopes are available. Types of microscopes A) Visible light as source of illumination i) Bright-field microscope, commonly known as light microscope or optical microscope. ii) Dark field microscope iii) Phase contrast microscope B) UV rays as source of illumination - Flouroscence microscope C) Electron beam forms image of specimen - Electron microscope D) Surface forces form image of specimen - Atomic force microscope (AFM)