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