Microbiology MCQs (Quiz 4) Posted on June 7, 2026June 10, 2026Author agropublishers 0 1. The genetic material in bacterial plasmids consists of ___________________ RNA Polysaccharide Protein Circular DNA 2. An antibiotic targets peptidoglycan synthesis. Which microbial structure will be most affected? Capsule Cell wall Ribosome Plasma membrane 3. The plasma membrane mainly consists of _________________ Phospholipids and proteins Chitin Peptidoglycan Cellulose 4. A Gram-positive bacterium is generally more susceptible to lysozyme because it possesses a ____________ Thick outer membrane Thick exposed peptidoglycan layer Protein capsule Thin peptidoglycan layer 5. Which statement best explains why Robert Hooke’s observations were important to biology? He identified the process of cell division He discovered DNA within cells He provided the first recorded description of cells, laying the foundation for cell theory He proved that all cells contain nuclei 6. In microbiology, chemotaxis refers to __________ Movement in response to chemical stimuli Protein synthesis Capsule formation Cell division 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 _____________________________________ Sterilization occurs faster because air helps heat transfer 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 8. The outermost layer of many bacterial capsules is predominantly _________________ Phospholipid Polysaccharide Peptidoglycan Protein 9. Which of the following discoveries occurred during the golden age of microbiology (1857–1914)? Development of the germ theory of disease Discovery of penicillin Discovery of DNA structure First observation of bacteria by Leeuwenhoek 10. The scientist associated with antiseptic surgery is _________________ Edward Jenner Robert Brown Alexander Fleming Joseph Lister Loading … Question 1 of 10 Microbiology MCQs (Quiz 4)
