Microbiology MCQs (Quiz 4) Posted on June 7, 2026June 10, 2026Author agropublishers 0 1. Which of the following discoveries occurred during the golden age of microbiology (1857–1914)? Development of the germ theory of disease First observation of bacteria by Leeuwenhoek Discovery of DNA structure Discovery of penicillin 2. A laboratory technician sets the autoclave to 121°C for 15 minutes but forgets to close the exhaust valve. The most likely outcome is _____________________________________ Sterilization occurs faster because air helps heat transfer The autoclave explodes immediately Air is not completely removed, preventing steam from reaching 121°C, leading to failed sterilization Effective sterilization, but a longer time is needed 3. The genetic material in bacterial plasmids consists of ___________________ RNA Circular DNA Polysaccharide Protein 4. The outermost layer of many bacterial capsules is predominantly _________________ Protein Phospholipid Polysaccharide Peptidoglycan 5. Which statement best explains why Robert Hooke’s observations were important to biology? He discovered DNA within cells He provided the first recorded description of cells, laying the foundation for cell theory He identified the process of cell division He proved that all cells contain nuclei 6. The plasma membrane mainly consists of _________________ Peptidoglycan Cellulose Chitin Phospholipids and proteins 7. In microbiology, chemotaxis refers to __________ Cell division Movement in response to chemical stimuli Protein synthesis Capsule formation 8. A Gram-positive bacterium is generally more susceptible to lysozyme because it possesses a ____________ Thin peptidoglycan layer Thick outer membrane Protein capsule Thick exposed peptidoglycan layer 9. The scientist associated with antiseptic surgery is _________________ Robert Brown Alexander Fleming Joseph Lister Edward Jenner 10. An antibiotic targets peptidoglycan synthesis. Which microbial structure will be most affected? Plasma membrane Capsule Cell wall Ribosome Loading … Question 1 of 10 Microbiology MCQs (Quiz 4)
