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