MICROBIOLOGY EXAM 1 NEWEST ACTUAL EXAM COMPLETE 350 QUESTIONS AND CORRECT DETAILED ANSWERS (VERIFIED ANSWERS) |ALREADY GRADED A+

1 | P a g e MICROBIOLOGY EXAM 1 NEWEST 2024-2025 ACTUAL EXAM COMPLETE 350 QUESTIONS AND CORRECT DETAILED ANSWERS (VERIFIED ANSWERS) |ALREADY GRADED A+ All of the following are associated with filtration EXCEPT: A) nitrocellulose or plastic membrane filters. B) varying thicknesses of membrane filters used. C) HEPA filters are used to filter air. D) viruses and proteins can be trapped by some filters. E) sterilization of heat-sensitive materials. - ANSWER- B) varying thicknesses of membrane filters used. Describe some factors that can either increase or decrease the effectiveness of antimicrobial agents. - ANSWER- duration of exposure- ->in general, longer/increased exposure time, increases efficiency of the agent concentration of the agent-->in general increase concentration of agent increases efficiency...however saturable once agent reaches max kill, rate increases, does not drop efficiency. 2 | P a g e presence of organic debris-->debris may be food, feces, blood, vomit, skin, hair, etc. it also blocks agent from receiving microbes: may need to pre clean. in general increased debris decreases efficiency. surface features-->in general rougher/more porous surface, decreases efficiency. ideally wants agent with low surface tension. *water has high tension surface *tension goes in to cracks/pores temperature-->in general a temperature increases efficiency. usually increased temperature reduces time required to clean and reduces concentration level. *less to do with agent *more to do with microbe population size(how many microbes are present)-->in general larger population/more microbes present, decreases efficiency. most agents have a defined kill rate. the larger the population the more time to kill eg.. agent-->50% per minute kill rate(pop. a. 100-50-25-12-6-3-1-0) 1 minute to kill population composition-->in general, more diverse/mixed population, decrease efficiency. population may be diverse in many different groups of microbes present, presence of endospore forming species, age of cells(older/mature cells more difficult to kill) eg.. pop. b. (1000-500-250-125-62-31-16-8-4-2-1-0) 11 minutes to kill 3 | P a g e The spores of which of the following microbes are the most resistant to every known sterilization technique? - ANSWER- Bacillus stearothermophilus Match the pioneer(s) in microbiology with their accomplishment(s). Fleming Snow Jenner Ehrlich Watson & Crick - ANSWER- idk Fleming- immunologist and discovered lysosome and penicillin Snow- epidemiology and infection control (emerging infectious disease) Jenner- Immunology (Developed smallpox immunization) Ehrlich - chemotherapy Watson & Crick - discovered DNA molecule Compare and contrast the three domains identifies by Woese-Eukarya, Bacteria, and Archaea. - ANSWER- written A bacterial capsule A. is generally composed of polysaccharide B. facilitates nonspecific adherence 4 | P a g e C. is antiphagocytic D. is external to the cell wall E. all of the above - ANSWER- E. all of the above A bacterial cell that is moving away from a toxic pollutant in the environment during the daylight is said to exhibit - ANSWER- negative chemotaxis If a microbiology lab technician left the safranin out of the Gram stain procedure, what would be the result? - ANSWER- Gram-positive cells would be purple, and Gram negative cells would be colorless. The number of bacteria resulting from the growth of one bacterium through five generations: - ANSWER- idk Which of the following quantification techniques can distinguish between living and dead cells in a culture? A) microscopic counts B) dry weight C) metabolic activity D) a Coulter counter E) turbidity - ANSWER- C) metabolic activity A cell that uses an organic carbon source and obtains energy from a light would be called a