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