Microbiology EXAM 1 (Chapters 1,3,4 and 6) Questions With Complete Answers.

Microbiology EXAM 1 (Chapters 1,3,4 and 6) Questions With Complete Answers. microobiology The study of organisms too small to be seen with the naked eye is _______ viruses, bacteria, algae, protozoa, fungi and helminths What are the six major groups of microorganisms? 3.5 billion years ago Single celled organisms arose ______ million years ago and have been shaping our earth ever since Eukaryotes = have a true nucleus (include protozoa, fungi, plants and animals) Prokaryotes= lack a true nucleus, include bacteria and archae The two main divisions of single celled organisms are? meaning? Each group includes which kingdoms? Ubiquitous means found everywhere- land, water, oceans, ice caps, deserts, deep sea vents What does it mean to say bacteria are ubiquitous? Give examples bacteria- Food, beer and wine production. fungi- antibiotics How do humans use microorganisms? Examples biotechnology- manipulation for production of products Genetic engineering- GMOs recombinant DNA- E. coli making human insulin bioremediation- cleaning up oil spills Give an example of how humans use microorganism fin biotechnology? genetic engineering? recombinant DNA? bioremediation? any agent, such as a bacteria, virus, algae, protist or fungi that causes disease (nearly 2000 different microbes are pathogenic) What is a pathogen? Plasmodium falciparum- pathogenic protists transmitted by mosquitoes 700,000-1.2 million people killed annually netting for prevention What causes malaria? How severe is this disease? Prevention? *Gastric ulcers *links between bacteria, viruses and cancers * virus and diabetes Diseases once thought noninfectious are now found to be caused by microbes. Examples soil and water The majority of microorganisms live in __________ and __________ and are either harmless or beneficial. An organism that is harbored in or on another (a host) and causes harm. What is a parasite? belief that life can come from non-life Redi (1600s) and Pasteur (1800s) disproved What is spontaneous generation? Who and when was it disproved? Hooke- make first microscope 1600s, named "cells" Antonie van Leewenhoek- made a crude microscope, saw "animalcules" in rainwater and scraped teeth Development of the microscope- Hooke? Antonie van Leewenhoek 1980s- Discovery of restriction enzymes. 1980s- invention of the PCR technique, copies of DNA 1980s + - importance of biofilms in infectious diseases 2000s- importance of small RNAs What are some of the exciting research and findings in the century of biology? 1970s Discovery of _________ enzymes 1980s invention of the _____ technique for making multiple copies of DNA. 1980s and beyond- the importance of ________ in infection disease 2000s- the importance of small ______ John Tyndall- microbes in dust and air have high heat resistance Ferdinand Cohn- discovered endospores - sterile= completely free of all life including endospores and virus particles What contribution did these men make to the discovery of spores and sterilization? * John Tyndall * Ferdinand Cohn Koch- linked a specific microorganism to a disease Anthrax to Bacillus anthracis Holmes and Semmelweis- showed connection between maternity ward women's infections and doctors who had been working in the autopsy room What contribution did these men make to the discovery of spores and sterilization? * Robert Koch * Dr. Oliver Wendell Holmes and Dr. Ignaz Semmelweis Lister- first to utilize hand washing and misting with antiseptic chemicals in operating room - techniques became the foundations of modern microbial control What contribution did these men make to the development of aseptic techniques? *Joseph Lister Pasteur- invented pasteurization, vaccine for rabies, showed human diseases could arise from infection Koch- germ theory of disease, Koch's Postulates What contribution did these men make to the development of aseptic techniques? * Pasteur *Robert Koch Division, Kingdom, Phylum, (Division), Class, Order, Family, Genus, Species Underline Genus species name or italicize Capital Genus name and lowercase species name May abbreviate genus name if already stated H. sapien What is the system for naming/classification? Inoculation Incubation Isolation Inspection Identification What are the Five I's? culture= to grow medium= nutrient rich material for growing microbes inoculation= introduce microbes sterile= free of life Briefly define/describe each of the words as it pertains to inoculation. *culture * medium * inoculation *sterile 20-40 degrees celcius What are the usual temperatures for incubation? chemical composition of media is known What is meant by a defined (synthetic) media? chemical composition of media is not known (at least one component) Example: blood, serum, milk, yeast extract, infusions What is a complex media? General purpose media- grows a wide spectrum of bacteria Enriched media has vitamins, nutrients, growth factors added for fastidious bacteria (bacteria that have specific growth requirements) Compare and contrast general purpose media and enriched media? Selective media has one or more ingredients that "selects" one type of microbe to grow Ex: MacConkey agar- selects for gram negative bacteri Differential media- allows multiple types of microbes but shows a visible difference between colonies (dyes are frequently used as differential agents) Ex: Blood agar- beta, alpha, gamma hemolysis Could show differences in- *different colored colonies * different media colors * precipitates * gas bubbles What is the difference between selective and differential media? Hemolysis= the breakdown of RBC by hemolyase enzymes (lyse RBC to release hemoglobin) beta hemolysis= complete breakdown of RBC,clear area alpha hemolysis= incomplete lysis, green area gamma hemolysis= no lysis, no change in area What is hemolysis? Compare and contrast beta, alpha and gamma hemolysis? separation of species from each other obtain pure colonies, separate colonies to make a pure culture (only a single species) What is the purpose of isolation? Spread plate method= we did in lab, a small amount of culture is spread over an agar surface and streaked in a pattern that gradually thins of the sample Loop dilution method- we did in lab, a small sample of liquid is gradually diluted over a succession of liquid agar tubes, poured into petri dishes (microbes grow within media) Spread plate method= we did not do, small sample of liquid is spread out using a hockey stick Compare and contrast the three methods of isolation. *Streak plate method * Loop Dilution method * Spread Plate method pure culture= one species of microbe only mixed culture= more than one species of known bacteria contaminated culture= species of unknown bacteria Compare and contrast pure culture, mixed culture, contaminated culture. macroscopic analysis microscopic analysis immunologic testing phenotypic testing genotypic testing How is a microbe profile determined? (Inspection and Identification) Magnification= enlarge an object Resolution= distinguish between two adjacent objects (human eye is .2 mm) Contrast= see difference between an object and its surroundings What are the three properties of an effective microscope? bending or change in the angle of the light ray as it passes through a medium such as a lens or air *Oil has same optical properties as glass, peripheral light does not bend as much as it would scatter in air *Blue filter * decrease the amount of light, raise the diaphragm What is refraction? How can refraction be lessed? light microscope, uses visible light, most common type 2000x What is a bright field microscope? What is it used for? *visualize cells on a dark background Opposite of light microscopy undiffracted light doesn't pass through specimen resulting in bright image against dark background useful in viewing UNSTAINED organisms *best for viewing living organisms that would be distorted by drying or staining When observing unstained living microorganisms or microorganisms that are hard to stain and spirochetes that are poorly defined in bright field What is a dark field microscope? What is it used for? *Cell structures differ in density, enough that they can alter the light that passes through them in subtle ways. This microscope contains devices that transform the subtle changes in light waves passing through the specimen into differences in light intensity. Denser cell parts such as organelles alter the pathway of light more than less dense regions (like cytoplasm). *living cells *unstained * decreased resolution Most of the detail of living cells is undetectable in bright field microscopy because there is too little contrast between structures with similar transparency and there is insufficient natural pigmentation. However the various organelles show wide variation in refractive index, that is, the tendency of the materials to bend light, providing an opportunity to distinguish them. Cilia and flagella, for example, are nearly invisible in bright field but show up in sharp contrast in phase contrast. Amoebae look like vague outlines in bright field, but show a great deal of detail in phase. Most living microscopic organisms are much more obvious in phase contrast. What is a phase contrast microscope? What is it used for? UV radiation source dyes that flourescence are used and when bombarded by UV rays, glow * useful for diagnosing infection by bacteria, protists, viruses What is the principle behind a fluorescent microscope? What is it used for?