MICRO 231 Exam 1 (Topics 1-4) Questions with Correct Answers Latest Update 2025/2026

MICRO 231 Exam 1 (Topics 1-4) Questions with Correct Answers Latest Update 2025/2026 how long have prokaryotes been present on earth - Answers 3.8 billion years what type of prokaryotes left fossil remains in some soft shale rocks that are about 3.5 billion years old - Answers cyanobacteria When was the existence of microbes first noted by humans using a microscope - Answers 1600s Hooke before microscopes, what processes were humans aware of that were caused by microbes - Answers decay, fermentation what is the plague, what is it caused by, why is it considered to have had a major effect on human history - Answers bubonic plague, caused by bacterium Yersinia pestis, killed about 25% of Europe's population what type of microbes did Hooke observe and describe - Answers bacteria, protozoans, yeast what did Hooke use to observe the microbes - Answers glass lens, small microscope what infectious disease did Semmelweis try to control or eradicate in the hospital facilities he had authority over, what method did he use - Answers childbed fever, hand washing which bacterium is now known to have been the cause of childbed fever - Answers streptococcus what infectious disease did John Snow try to control or eradicate from the area of London - Answers cholera what method did John Snow use to try to eradicate cholera - Answers epidemiology, remove handle from water pump what is the scientific name of the pathogenic bacterium that causes cholera - Answers vibrio cholerae what area of study in the public field of health microbiology did this work by Snow help to establish - Answers epidemiology what infectious disease did Jenner try to control or eradicate in the area of London - Answers small pox what type of microbes cause small pox - Answers variola virus what method did Jenner use to attempt disease control - Answers cowpox lesion what were the major experiments that Pasteur carried out which led tot major discoveries in microbiology - Answers fermentation, spontaneous generation, silk worm disease, rabies vaccine fermentation - Answers experiment to find out why beer sours, heat prevents growth spontaneous generation - Answers can something arise from nothing, airborne microbes silkworm - Answers verify certain microorganisms cause certain disease, protozoa rabies - Answers experiment if vaccines work what were the major techniques that Koch and his coworkers devised to enable them to study microorganisms, especially some cultural bacteria - Answers staining techniques, isolating colonies, streaking What are Koch's postulates - Answers 1. The same pathogen must be present in every case of the disease. 2. The pathogen must be isolated from the diseased host and grown in pure culture. 3. The pathogen from the pure culture must cause the disease when it is inoculated into a healthy, susceptible laboratory animal. 4. The pathogen must be isolated from the inoculated animal and must be shown to be the original organism. how are postulates carried out - Answers obtaining pure cultures what are some materials/requirements needed to carry out the postulates - Answers agars, aseptic technique using postulates, which pathogenic bacteria did Koch determine to cause what specific infectious disease - Answers anthrax/bacillus anthracis what method did Koch and his coworkers use to obtain pure cultures of bacteria - Answers streaking for isolation what were some of the common research interest that Pasteur and Koch shared - Answers both studied anthrax why was surgery before Lister more dangerous, uncertain procedures than it is today for patients - Answers greater risk of post op infection, could lead to death because it was not sterile what influence did Pasteur's work have on Lister's - Answers his papers on microorganisms interested him, used phenol as a mist based on this how did the ability of certain chemicals to remove foul odors affect Lister's ideas and work - Answers soaking bandages/dressings in dilute phenol before applied to wound would eliminate odor/infection and reduce post op sepsis how were Lister's steps to carry out antiseptic surgery later modified to enable aseptic surgery - Answers surgeons wash hands well with cleaning solution and disinfect wound dressing/surgical instruments before use which steps involved in aseptic technique are related directly to the work that Semmelweis, Pasteur, Koch, and Lister carried out - Answers Bunsen burner and air contamination flaming the loop definition of cell in biology and microbiology - Answers smallest structure of an organism are all microorganisms composed of cells, if not, which are not - Answers no- virus, viroids, prions