ATHABASCA BIOL 325- MIDTERM | QUESTIONS AND ANSWERS | LATEST 2024/25

ATHABASCA BIOL 325 - MIDTERM | QUESTIONS AND ANSWERS | LATEST 2024/25 Definition of microorganism a unicellular organism that is simple in structure and cannot be seen with the naked eye The naming process of organisms Developed by Carolus Linnaeus. Each organism is assigned two names - the genus (capitalized) and the species (lowercase) all of which is italicized. The names can describe an organism, honor a researcher or identify the habitat of a species. Seven major gr oups of microorganisms 1) Bacteria 2) Archaea 3)Fungi 4)Protozoa 5)Algae 6)Viruses 7)Multicellular animal parasites Biological properties of Bacteria (8) · Simple, single celled organisms · Unicellular · Prokaryotic · Can be bacillus, coccus or spiral shap ed · Enclosed in cell walls composed of peptidoglycan · Reproduce via binary fission · Use organic chemicals for nutrition · Motility via flagella Biological properties of Archaea (5) · Prokaryotic · Cell walls lacking peptidoglycan · Found in extreme environments · Three types: methanogens, extreme halophiles and extreme thermophiles · Not known to cause disease in humans Biological properties of Fungi (6) · Eukaryotic · Unicellular or multicellular · Cannot carry out photosynthesis · Cell wall composed of chitin · Consists of yeasts, molds and slime molds · Can reproduce sexually or asexually Biological properties of Protozoa (6) · Unicellular · Eukaryotic · Move via pseudopods, flagella or cilia · Live as free entities or as parasit es · Can reproduce sexually or asexually · Some are photosynthetic Biological properties of Algae (8) · Photosynthetic · Eukaryotic · Can reproduce sexually or asexually · Usually unicellular · Cell walls composed of cellulose · Abundant in freshwater, saltwater, soil and in association with plants · Produce oxygen and carbohydrates · Play vital role in balance of nature Biological properties of Viruses (5) · Very small · Acellular · Surrounded by protein coat · Can only reprodu ce via a host · Not living Biological properties of Multicellular animal parasites (2) · Eukaryotic · Consist of flatworms and roundworms Four habitats where microorganisms can be found 1) Soil 2)Salt water 3)Thermal vents 4)Human skin Explanation of what is meant by pathogenic microorganism has the potential to produce disease Compare observations of Anton van Leeuwenhoek and Robert Hooke Anton van Leeuwenhoek: using a microscope was able to see individual cells, developed the cell theory Robert Hooke: observed live microorganisms through a magnifying lens Accomplishments of Linnaeus Created the nomenclature/naming system for organisms that is used today -binomial nomenclature Definition of golden age of microbiology rapid advances, spearheaded by Pasteur a nd Koch led to the establishment of microbiology as a science Discuss the work of Pasteur found that yeasts ferment sugars to alcohol and that bacteria can oxidize the alcohol to acetic acid. Also, showed a causal relationship between microorganisms and di sease. Discuss the work of Lister introduced the use of a disinfectant to clean surgical wounds in order to control infections Discuss the work of Koch proved that microorganisms cause disease Discuss the work of Ehrlich used the first synthetic chemotherapeutic agent. Contributions made by Jenner demonstrated that inoculation with cowpox material provides humans with immunity to smallpox. Helped develop vaccines Contributions made by Fleming observed that the Penicillium fungus inhibited the growth of bacterial culture. Discovered penicillin and helped discover antibiotics Contributions made by Lancefield proposed that streptococci be classified according to serotypes based on certain components in the cell walls of the ba cteria. Rapid identification of specific pathogenic streptococci based on immunological techniques What is the theory of spontaneous generation? life an arise spontaneously from nonliving matter such as dead corpses and soil. How was the theory of spontaneous generation disproved? Pasteurs experiment demonstrated that microbes are present in nonliving matter such as air, liquids and colds What as Pasteurs experiment that disproved the theory of spontaneous generation? 1) Poured beef broth into a long -necked flask (with micro -organisms present in the broth) 2)Heated the neck of the flask and bent it into an S shape; he then boiled the broth for several minutes (no micro -organisms present) 3)Microorganisms did nit cooer in the coo led solution even after long periods of time What is pasteurization? How was it discovered? Pasteurization is a heating process used to kill bacteria in some alcoholic beverages and milk. It was discovered by Pasteur when he was trying to find a solution to a spoilage problem so he heated bear and wine just enough to kill most of the bacteria that caused the spoilage Discuss the germ theory of disease Idea that microorganisms have similar relationships with plants and animals -- this meaning that microorga nisms might cause disease How did joseph Lister apply the germ theory to medical procedures? He had noticed that physicians who did not disinfect their hands, routinely transmitted infections from one patient to another. He had heard of Pasteur connecting microbes to animal diseases and he knew that phenol killed bacteria so he began to use phenol solution on surgical wounds. It was such a hit at controlling the spread of infections that many other surgeons adopted the idea. Describe the contribution of Rob ert Koch First proof that bacteria actually cause disease. He developed his postulates which are a sequence of experimental steps for directly relating a specific microbe to a specific disease. What are Koch's postulates? 1) The bacteria must be present in every case of the disease 2) The bacteria must be isolated from the host with the disease and grown in pure culture 3) The specific disease must be reproduced when a pure culture of the bacteria is inoculated into a healt hy susceptible host 4) The bacteria must be recoverable from the experimentally infected host Define vaccine an injected or inhaled substance that protects humans or other animal from infection by the active form of the given microorganism Define biogenesi s living cells can arise only from preexisting living cells Compare the processes of fermentation and pasteurization Fermentation : yeasts convert sugars to alcohol in the absence of air Pasteurization: a process in which liquids are heated to kill most mic robes Compare virulent and avirulent microorganisms Virulent: organisms able to cause disease Avirulent : unable to cause disease Describe the source and general action of antibiotics Microbiologists were looking for a substance that could destroy pathogeni c microorganisms without damaging the infected animal or human. Chemicals produced naturally by bacteria and fungi to act against other microorganisms are antibiotics. The first antibiotic - penicillin was discovered by accident by Alexander Fleming. Descr ibe the discovery of penicillin by Alexander Fleming Fleming almost tossed out some culture plates that had been contaminated by mold. When he took a second look at the curious pattern of growth on the contaminated plates. Around the mold was a clear area where bacterial growth had been inhibited. He was therefore looking at a mold that could inhibit the growth of bacteria, it was later identified as Penicillium notatum . Explain how drug -resistant microorganisms develop Drug resistance results from genetic changes in microbes that enables them to tolerate a certain amount of an antibiotic that would normally inhibit them. What is the purpose of aseptic techniques in microbiology? Aseptic techniques are used to prevent microbial contamination Describe the exp eriment performed by Edward Jenner to protect individuals from smallpox. He collected scrapings from cowpox blisters. Then he inoculated a healthy volunteer with the cowpox material by scratching the persons arm with a pox -contaminated needle. The scratch turned into a raised bump. A few days later, the volunteer became mildly sick but recovered and never again contracted cowpox or smallpox. This was the first vaccination. What was Erlich's magic bullet? Chemotherapeutic agent salvarsan because it was considered to offer salvation from syphilis and contained arsenic Define bacte riology the study of bacteria