Microbiology MCQs (Quiz 9) Posted on June 8, 2026June 10, 2026Author agropublishers 0 1. Joseph Lister’s introduction of antiseptic surgery significantly reduced ____________________ Fermentation in food Tuberculosis transmission Viral infections Post-operative infections and mortality 2. Which principle is involved in sterilization by membrane filtration? Heat destruction Radiation damage Chemical inactivation Physical separation 3. Which microorganism contains 70S ribosomes? Yeast Escherichia coli Paramecium Amoeba 4. In microbiology, UV radiation is mainly used for ___________ Sterilizing culture media Surface disinfection Sterilizing surgical instruments Deep tissue sterilization 5. Chlorine is most widely used in public health for the disinfection of _____________ Water Surgical instruments Culture media Hospital floors 6. ______________ radiation is most commonly used for sterilizing disposable syringes, catheters, and surgical gloves Infrared radiation Ultraviolet radiation Microwaves Gamma radiation 7. Most pathogenic microorganisms obtain both energy and carbon from ______________ Inorganic chemicals and CO₂ Organic compounds Sunlight and CO₂ Sunlight and organic compounds 8. The germicidal effectiveness of Ultraviolet (UV) radiation is greatest at approximately __________ 500 nm 900 nm 254 nm 700 nm 9. Agar exhibits thermal hysteresis because _______________ Its melting temperature is much higher than its solidification temperature Bacteria degrade it It contains proteins It changes color during heating 10. The primary lethal effect of UV radiation on microorganisms is the formation of ________ in DNA Peptidoglycan cross-links Thymine dimers Disulfide bonds ATP molecules Loading … Question 1 of 10 Microbiology MCQs (Quiz 9)
