MicroLec_Midterm_1_S2011_aKEY

MicroLec_Midterm_1_S2011_aKEY - Microbiology Exam I...

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Unformatted text preview: Microbiology Exam I February 22, 2011 Name (Print): ____________________ READ AND SIGN THE FOLLOWING PARAGRAPH BEFORE BEGINNING THE EXAM. Your exam will not be graded unless you’ve signed the statement. I pledge that I will neither seek help nor offer help to any other student while taking this exam. I will make every effort to assure that no other student can see my answers. I also state that I have no aids, such as crib sheets and that I know of none used by other students. I have not conferred with any student who has already seen the exam. Signed:_____________________________________ INSTRUCTIONS: *No electronic devices of any kind are allowed during the exam. Turn your cell phone OFF and put away any electronic device you have (calculator, iPod, laptop, fuel injector, etc). * Print and bubble in your name: Last name, space, first name. * Bubble in your campus ID number (on your ID card) * If you have a question about a question, please ASK. * At the end of the exam, turn in both the scantron sheet and this exam. The exam will be returned to you later. 1. Who insisted that his physicians wash their hands after examining each patient? A. B. C. D. E. 2. Semmelweis Ehrlich Lindahl vanLeeuwenhoek Lister Escherichia coli is about 2 µm in length. How many of these cells would comprise a chain 1 mm long? A. B. C. D. E. 5 X 106 5 X 105 5000 500 50 3. The life expectancy of humans in the USA was about 47 years in the year 1900. In the year 2000 it was about 75 years. Which of the following contributed to the dramatic change? A. B. C. D. E. 4. Which of the following are eukaryotes? A. B. C. D. E. 5. No. She would need to inject the diseased wildebeests with the isolated bacterium. No. She would need to identify the bacterium. No. She would need to demonstrate that the bacterium is pathogenic to other mammals. No. She would need to isolate the bacterium from the newly diseased animals. Yes A researcher isolates a soil microbe from the UMBC Quad. He determines that the organism has 70s ribosomes. This organism could be A. B. C. D. E. 7. Viruses Bacteria Fungi Prions More than one of the above A disease occurred in some of the wildebeests in the UMBC wildlife preserve. A graduate student examined the diseased wildebeests. She isolated a bacterium that was found in all of the diseased wildebeests but none of the healthy ones. She inoculates the bacterium into healthy wildebeests and they contract the disease. Has she demonstrated that this bacterium is the infective agent? A. B. C. D. E. 6. Sanitation Hygiene Antibiotics All of the above None of the above A bacterium A yeast An archeae Two of the above All of the above. Eukaryotes have 80s AND 70s A researcher has a viroid in her freezer. It was probably isolated from A. B. C. D. E. A plant A fungus A mammal A bacterium Could be more than one of the above. 2 8. A pathogenic agent is isolated which contains both DNA and RNA. It is most likely a A. B. C. D. E. 9. Prion Protozoan Virus Helminth Could be more than one of the above Streptococcus mutans produces a dextran capsule when grown in the presence of sucrose. This bacterium causes A. B. C. D. E. Strep throat Caries Conjunctivitis Anthrax More than one of the above 10. Which bacterial structure is MOST likely to be a target for a virus? A. B. C. D. Outer Membrane Protein Ribosome Nucleoid Storage granule 11. A bacterium with peritrichous flagella ‘runs’ when the flagella rotate in a counterclockwise direction. A bacterium with monotrichous flagella ‘runs’ when the flagellum rotates in a clockwise direction. A. True B. False 12. Which flagellar arrangement is pictured in the picture? A. B. C. D. E. Peritrichous Oligotrichous Amphitrichous Lophotrichous Try’n’trichous 13. The fungi A. B. C. D. E. Are Prokaryotic Are extremophiles Have no cell wall Are Eukaryotic More than one of the above 3 14. I. The Gram positive and Gram negative cell walls both serve as permeability barriers. II. Gram negative cell walls have LPS which can be an endotoxin. A. B. C. D. Both statements are true Neither statement is true Only statement I is true Only statement II is true 15. During which phase(s) of growth is there no cell division? A. B. C. D. E. Lag Log Stationary Death More than one of the above. 16. Eosin Methylene Blue agar is used to isolate intestinal bacteria. Methylene Blue inhibits Gram Positive bacteria. The lactose in the media allows one to determine if the organisms on the plate ferment lactose. Eosin Methylene Blue agar is A. B. C. D. Selective Differential Both Neither 17. On the right is a graph of the Absorbance measured on a spectrophotometer as a function of the concentration of bacteria. From this graph one might accurately conclude A. B. C. D. E. There is no lag phase when the concentration is measured with a Spec Stationary phase begins at about 5 X 108 cfu/ml Below about 5 X 106 cfu/ml the absorbance isn’t measurable The culture wasn’t grown long enough to see a death phase More than one of the above 4 18. Blood Agar is a differential medium. Which of the following statements is/are true? I. Blood Agar is a defined medium. II. Beta-Hemolysis is defined as the complete lysis of red cells. A. B. C. D. Both statements are true Neither statement is true Only statement I is true Only statement II is true 19. Mycoplasma pneumoniae is an atypical bacterium which causes a form of pneumonia. It is ‘atypical’ because it has no cell wall. Penicillin is a good choice to treat a Mycoplasma infection. A. True B. False C. Not enough information 20. What is the log2 8 (log, base 2, of 8)? A. B. C. D. E. 1 2 3 4 5 21. Which of the following will have the shortest generation time? A. B. C. D. E. E. coli growing at 30° C in a minimal defined medium at pH 5.5 with oxygen E. coli growing at 30° C in a rich complex medium with oxygen. E. coli growing at 37° C in a minimal defined medium with oxygen. E. coli growing at 40° C in a rich medium without oxygen. Cannot be determined from the information given. Too many variables changed 22. A bacterial culture has an initial concentration of 7.5 X 106 cfu/ml. After two hours of exponential growth, the concentration is 1.92 X 109 cfu/ml. What is the growth rate constant, k? log 2 = .3 A. B. C. D. E. log 7.5 = 0.88 log 1.92 = 0.28 0.25 generations/hour 1 generation/hour 2 generations/hour 3 generations/hour 4 generations/hour 5 For #23 to #27 A researcher isolates a Gram Positive rod shaped bacterium from the terrace in front of the Student Union. It grows on rich complex media and on Glucose defined media. When the culture is aerated it has a generation time of forty minutes at 37°C and two hours at 25°C . Under anaerobic conditions, its generation time at 37°C is also 40 minutes. It does not grow at 45°C. 23. This organism is A. B. C. D. E. Microaerophilic Aerotolerant An obligate aerobe An obligate anaerobe A facultative anaerobe 24. The bacterium produces endospores. A. True B. False C. Not enough information 25. This organism is a A. B. C. D. E. Psychrotroph Thermophile Psychrophile Mesophile Not enough information 26. The growth rate constant at 25°C with aeration is A. B. C. D. E. 0.5 generations/hour 2 generations/hour 120 minutes ½ hour per generation 4 grams 27. I. The bacterium might have mycolic acid in its cell wall. II. The bacterium might have an outer membrane. A. B. C. D. Both statements are true Neither statement is true Only statement I is true Only statement II is true 6 28. Chloramphenicol is an antibiotic which inhibits protein synthesis. It is classified as bacteriostatic. Thus it A. Inhibits bacterial growth B. Kills bacteria C. Reduces the growth rate of bacteria 29. I. Filtration can remove bacteria from liquids but not from air. II. Ultraviolet light causes the formation of free radicals: highly reactive molecules. A. B. C. D. Both statements are true Neither statement is true Only statement I is true Only statement II is true 30. You are hired by Safeway to control bacterial growth in their ground beef. Which of the following strategies is useful for doing so. A. B. C. D. E. Pasteurize the ground beef Irradiate the ground beef with Gamma rays Autoclave the ground beef Irradiate the ground beef with Ultraviolet light More than one of the above 31. Salting, drying and adding sugar are all means to inhibit bacterial growth. These all serve to A. B. C. D. E. 32. Cause the formation of free radicals Change the internal temperature of the cell Limit water in the cytoplasm All of the above None of the above. Refrigeration reduces the growth of microbes. Freezing kills all of them. A. True B. False 33. Which of the following is smallest? A. B. C. D. E. coli Protozoans Prions Viruses 7 34. Refer to the graph below. This could represent A. Treatment at 80°C of two different cultures of E. coli, starting at different concentrations B. Treatment of cultures starting at the same concentration of E. coli and of Staphylococcus aureus with 0.2 % bleach C. 75°C Treatment of cultures of E. coli and of Bacillus subtilis endospores starting at different concentrations D. Two of the above E. All of the above 35. The rate of killing in the graph above is A. B. C. D. E. Exponential in curve I, arithmetic in curve II Exponential in curve II, arithmetic in curve I Exponential in both curves Arithmetic in both curves None of the above. The kill rate is linear. 36. A 26-year-old female presents with flaccid paralysis. She had consumed some beets from a home-canned jar of beets two days before. What disease does this patient likely have? A. B. C. D. Tetanus Botulism Pneumonia Any of the above 37. As a physician, what would you order to confirm your diagnosis? A. B. C. D. Test the jar of beets for the presence of a Gram negative rod Test the patient for infection by a Gram positive coccus Test the jar of beets for the presence of a toxin All of the above 8 ...
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This note was uploaded on 02/24/2012 for the course BIOL 275 taught by Professor Sandoz/shreirer during the Spring '08 term at UMBC.

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