Microbiology MCQs (Quiz 7) Posted on June 8, 2026June 10, 2026Author agropublishers 0 1. Agar begins to solidify at temperature ~ ______________°C after cooling from its molten state 90-100 15-20 65-70 40-45 2. Which microscope is most suitable for the routine identification of bacterial cell shape and arrangement in stained preparations? Scanning electron microscope Dark-field microscope Bright-field microscope Transmission electron microscope 3. Why is air removal essential before sterilization begins in an autoclave? Air damages equipment Air reduces steam penetration and effective temperature Air increases microbial growth Air causes media solidification 4. A bacterium moves away from a disinfectant solution. This is an example of ___________________ Phototaxis Aerotaxis Positive chemotaxis Negative chemotaxis 5. A microbiologist wants to obtain isolated colonies from a mixed bacterial culture. Which medium would be most appropriate? Sterile water Buffer solution Nutrient agar plate Nutrient broth 6. What is the main sterilizing agent in an autoclave? Chemical disinfectants Dry heat Ultraviolet light High-pressure steam 7. ________________ is the primary source of agar used in microbiological media Bacteria Marine algae Protozoa Fungi 8. Joseph Lister applied which scientific principle to reduce surgical infections? Theory of Evolution Cell Theory Pasteur’s Germ Theory Koch’s Postulates 9. A microorganism that uses glucose as both an energy source and a carbon source is classified as a _____________ Photoautotroph Chemoheterotroph Chemoautotroph Phototroph 10. The medium containing agar and nutrients is called ___________ Selective medium Liquid medium Broth medium Solid medium Loading … Question 1 of 10 Microbiology MCQs (Quiz 7)
