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