Microbiology Exam Questions with 100% Correct Answers | Verified | Updated

Microbiology Exam Questions with 100% Correct Answers | Verified | Updated What is the concept of spontaneous generation? - answerliving organisms could develop from nonliving or decomposing matter Who challenged the concept of spontaneous generation by showing that maggots on decaying meat came from flies, not from the meat itself? - answerFrancesco Redi Who showed that mutton broth boiled in flasks and then sealed could still develop microorganisms, which supported the theory of spontaneous generation? - answerJohn Needham Who showed that flasks sealed and then boiled had no growth of microorganisms? - answerLazzaro Spallanzani Who proposed that air carried germs? - answerSpallanzani Who disproved the theory of spontaneous generation? - answerLouis Pasteur Who demonstrated that dust carried microbes and proved evidence for the existence of heat- resistant forms of bacteria? - answerJohn Tyndall Who showed that a silkworm disease was caused by a fungus? - answerAgostino Bassi Who demonstrated that the Great Potato Blight was caused by a water mold? - answerM. J. Berkely Who showed that the pebrine disease of silkworms was caused by a protozoan parasite? - answerLouis Pasteur Who developed a system of surgery designed to prevent microorganisms from entering wounds? - answerJohn Lister Who transformed the practice of surgery? - answerJohn Lister Who established the relationship between Bacillus anthracis and anthrax? - answerRobert Koch What are the Koch Postulates? - answer1.The microorganisms must be present in every case of the disease but absent from healthy individuals 2.The suspected microorganisms must be isolated and grown in pure culture 3. The same disease must result when the isolated microorganism is inoculated into a healthy host 4. The same microorganism must be isolated again from the diseased host Limitations of Koch's Postulates - answer-Some organisms cannot be grown in pure culture -Using humans in completing the postulates is unethical -Molecular and genetic evidence may replace What vaccination did Edward Jenner make? - answersmallpox vaccination What vaccinations did Pasteur produce? - answerchicken cholera, rabies and anthrax Who induced formation of dipped toxin-antitoxins rabbits - answerEmil von Behring and Shibasaburo Kitasato Who showed that the silkworm disease was caused by fungus? - answerBassi Who demonstrated that the Great Potato Blight of Ireland was caused by a water mold? - answerM.J. Berkeley Who showed that the perbrine disease of silkworms was caused by a protozoan parasite? - answerLouis Pasteur A simple morphology and lack a true membrane-delimited nucleus - answerprokaryotes What is a morphologically complex and has a membrane-enclosed nucleus? - answerEucaryotes What let to the discovery of viruses as disease causing agents? - answerbacterial filter that removed bacteria and larger microbes (Charles Chamberland) The five kingdom classification scheme is - answerthe Monera or Procaryotae, Protista, Fungi, Animalia, and Plantae What are ribozymes? - answerRNA molecules that form peptide bonds and perform cellular work and replication The three domain scheme is - answerBacteria, Archaea, and Eucarya The three domain scheme is based on? - answera comparaison of ribosomal RNA The earliest cells may have been - answerRNA surrounded by liposomes What are the three bacterial morphology? - answer-bacillus (little rod) -coccus (grain or berry) -spirillum (coiled or helical) What are the types of light microscopes? - answer-bright-field microscope -dark-field microscope -phase-contrast microscope -fluorescence microscopes What is a measure of how greatly a substance slows the velocity of light? - answerRefractive index The direction and magnitude of bending light in a microscope is determined by the _____ - answerrefractive indexes of the two media forming the interface Which microscope produces a dark image against a brighter background? - answerthe bright-field microscope What is the product of the magnifications of the ocular lens and the objective lens? - answerthe total magnification What is the total magnification of the bright field, dark field, and phase-contrast microscopes? - answer2000x What is the total resolution of the bright field, dark field, and phase contrast microscopes? - answer0.2um What is the purpose of the bright field microscope? - answerfor live and preserved stained specimens What is the purpose of the dark field microscope? - answerto observe living, unstained preparations Which microscopes are good for observing living cells? - answer-The Differential Interference Contrast Microscope -Phase-contrast microscope Which microscope enhances the contrast between intracellular structures having slight differences in the refractive index? - answerphase-contrast microscope Which microscope shows a bright image of the object resulting from the fluorescent light emitted by the specimen? - answerthe fluorescence microscope The fluorescence microscope exposes the specimen to what types of light? - answeruv, violet, or blue The distance between the center of the lens and focal point? - answerfocal length The shorter the focal point, the ______ the magnification - answergreater The shorter the wavelength, the ______ the resolution - answergreater The distance between the front surface of lens and surface of cover glass on specimen - answerWorking distance As the working distance decrease, the field of view _____ - answerdecrease As the field of view decrease, the light gets ____ - answerdimmer What is the purpose of adding the immersion oil? - answerto obtain more light by providing the same refraction energy as glass As the magnification increases, what happens to the focal length? - answerit decrease What is the charge of a bacteria cell surface? - answernegative charge What is the charge of basic dyes? - answerpositive charge What is the charge of acid dyes? - answernegative charge A thin, uniform film of bacterial growth on a glass slide in order to proceed with further staining for microscopic examination - answersmear The process by which organism is killed and firmly attached to microscope slide - answerfixation Heat fixation vs. Chemical fixing (not the procedure) - answer-heat fixation preserves overall shape but not internal structures -chemical fixing protects fine cellular structure and shape of larger, more delicate organisms What information does differential staining provide? - answerdivides microorganisms into groups based on their staining properties What is the most widely used differential staining procedure? - answergram staining Negative staining - answerthe bacteria is not stained; the background is stained What is shadowing in electron microscopy? - answercoating specimen with a thin film of heavy metal What is the total magnification of th