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