Microbiology MCQs (Quiz 8) Posted on June 8, 2026June 10, 2026Author agropublishers 0 1. _________________ ensures complete elimination of all microorganisms, including spores Disinfection Sterilization Antisepsis Sanitization 2. Agar, a jelly-like substance used to solidify microbiological media, is classified as a _______________ Lipid Protein Polysaccharide Nucleic acid 3. In microbiological studies, phenol was one of the earliest chemicals used as a _____________ Staining reagent Disinfectant Growth medium component Sterilizing agent 4. Many bacteria cannot use agar as a food source because they ______________ Lack enzymes capable of degrading agar Lack ribosomes Lack cell walls Cannot absorb carbohydrates 5. The concept that microorganisms cause putrefaction and wound infections led Joseph Lister to introduce ____________________ Aseptic culturing Vaccination Antiseptic surgery Antibiotic therapy 6. Eukaryotic 80S ribosomes consist of ________________ 20S and 60S subunits 30S and 60S subunits 30S and 50S subunits 40S and 60S subunits 7. Why is agar more suitable than gelatin for preparing solid culture media? Agar contains antimicrobial compounds Agar is cheaper than gelatin Agar remains solid at incubation temperatures and is not easily degraded by bacteria Agar is a better nutrient source 8. A microbiologist examining pigment production by bacterial colonies would benefit from agar’s ____________ Nutritional value Transparency Antimicrobial activity High melting point 9. Joseph Lister concluded that surgical infections were caused by _________________ Microorganisms entering wounds Changes in body temperature Bad air alone Spontaneous generation 10. Alcohol is widely used as an intermediate-level disinfectant because it _____________ Sterilizes culture media Kills many vegetative microorganisms but not all spores Replaces autoclaving Destroys all spores Loading … Question 1 of 10 Microbiology MCQs (Quiz 8)
