2018 Boyceville Invitational. Microbe Mission B

Transcription

1 Complete school name Team number 2018 Boyceville Invitational Microbe Mission B This test has 100 questions on 11 pages. 1. Place Team name and number on the top of this page and also on the answer sheet. ALL ANSWERS ARE TO BE PLACED ONLY ON THE ANSWER SHEET. Lack of team number will result in 5 point penalty 2. This test may be taken apart, however, IT MUST BE STAPLED NEATLY IN ORIGINAL ORDER WHEN TURNED IN. Staplers can be found at the proctor s desk. Out of order pages = 10point penalty, and non stapled test = 5 point penalty. 3. All answers that contain letters must be PRINTED IN CAPITAL LETTERS, or they will be counted wrong. 4. Large and small numbers must be written as exponents or they will be counted wrong. 5. You will have 50 minutes to complete the test. If you finish early, you may turn in test and leave. Time remaining will be announced periodically throughout the exam. Scattered at the bottom of some pages, in italics, are quality bad science jokes. These jokes have no point value; they are meant to amuse you if you are bored. Good luck and Merry Microbing!

2 Q1-4 pertain to the graph below 1. How many hours did it take the culture at 10 o C to reach a concentration of 5000/ ml? 2. What was the increase in the number of bacteria per ml grown at 15 C after three days? 3. What was the average increase per hour of the bacteria grown at 5 C over the interval shown on the graph? 4. How many bacteria per ml would you predict to be present if you grew the same culture at 7.5 C for 96 hour? Jerry Yventoshenko was still playing professional hockey at age 58. In one game, he scored 3 goals (aka a hat trick for the non-hockey informed). Ever since then he has been known as geriatric.

3 ! 5-7 Pertain to the figure below 5. At what time did the culture achieve a concentration of about 90,000 cells/cc (or ml)? 6. What is the approximate doubling time for the culture? 7. If you took a 0.1 cc sample after the culture had been growing for 15 hours, how many bacteria would you expect to find in this 0.1 cc sample? Be sure to express the answer in correct scientific notation or it will be counted wrong. What is the difference between swine flu and avian flu? A: Swine flu is treated with an oinkment and bird flu requires a tweetment

4 ! 8. The figure below represents the growth of two related ciliated protozoans. In The upper figure, cells of different species were grown in separate tubes. In the lower graph, both organisms were placed in the same tube. In both cases, the concentration of organisms was determined. The starting concentration of organisms was the same in all experiments. Which of the following statements is the most accurate of the mixed culture? A. The growth rate of P. caudatum begins to decline about 3 days after the start of the experiment B. At 8 days, P. aurelia has a growth rate greater than the growth rate of P. caudatum C. P. caudatum inhibits the growth of P. aurelia. D. P. aurelia stimulates the growth of P. caudatum Complete the following table for a compound microscope. For each question, e.g. Q 9, on the answer sheet write the value that should go in the corresponding box of the table. OCCULAR LENS MAGNIFICATION Convert each of the listed metric measurements to micrometers (µm). Each answer must have a unit, or it will be counted wrong. Answers must be in scientific notation, ex: 2 x 10 5, 3 x 10-2 etc. or it will be counted wrong mm cm nm OBJECTIVE LENS MAGNIFICATION 10x 6x Q9 8x Q10 160x Q11 10x 40x TOTAL MAGNIFICATION One upset student told the professor, I feel that you have frozen me out of my choice field of cryogenics.

5 15. If the diameter of the field of view is 350 µm, at 40x, what is the diameter of the field of view at 1000x? You are viewing an object using your 10X objective of your microscope. You measure the diameter of your field of view to be mm. 16. Convert the diameter of your field of view to µm. Use proper scientific notation. 17. You have a cell whose length you have determined to be 80 µm. If the cells are aligned end to end in a straight line, about many cells will cover the field of view. 18. Based on what you know about the relative sizes of microbes, what type of microbe are you looking at? Be specific. Eukaryotic or prokaryotic will be counted wrong For each number, indicate which type of microscope is the best for this task. Letters may be used more than once or not at all. Each question will have only one answer. A. Dissecting microscope C. Transmission electron microscope B. Regular light microscope D. Scanning electron microscope 19. Determining the 3-D shape of a virus 20. Observing a living causative agent of trichinosis 21. Examining the causative agent of rubella 22. Examining mobile bacteria with a size of 2 µm 23. Examining the surface of animal-like protists 24. Examining eukaryotic cells for the detailed structure of chloroplasts The following questions refer to microscopes A and B below. WRITE THE LETTER of the following four choices on your answer sheet. A. Only microscope A B. Only microscope B C. Either microscope A or B D. Neither microscope A nor B. A B!! 25. Produces the lower total magnification of the two scopes. 26. Allows the examination of the endoplasmic reticulum within the cell. 27. Provides detailed images of the cell surface. 28. Is used to observe protozoans moving

6 Questions pertain to the images below. The scale appears below each picture. A. B.!! 40µm 50µm C. D.!! 10 nm 50µm 29. Which image (A,B, or C) is from a scanning electron microscope? 30. Which image (A,B, or C) is from a transmission electron microscope? 31. Which image (A, B, or C) is from a light microscope microscope? 32. Arrange the organisms, A, B, C, D in order of size, largest to smallest. Your answer should be of the form A>B>C>D Pertain to the following table. Different organisms with different generation times were incubated for various times. Calculate the concentration of each organism at the end of the given time. Generation time Starting number 35. All of the following statements about the causative agent of AIDS are FALSE except A. It contains both DNA and RNA. B. It infects cells of the immune system. C. It is assembled in the nucleus of the cell. Length of time incubated 60 min 50/ml 4 hr min 100/ml 6 hr 34 D. The usual mode of transmission is through mosquito bites. Population at end of incubations 36. Which of the following pairs of diseases are typically the result of ingestion of contaminated water that has not been sterilized? A. malaria and tetanus B. anthrax and kuru C. hepatitis and tuberculosis D. cholera and giardiasis

7 Questions Pertain to the following pictures. The image appears beneath the letter. Match the disease caused by the organisms labeled A-G. Each disease will have one answer A. B. _1um C. D. _1 um 100nm. 100um E F. 10 um G. Organism not present 5um 37. Tapeworm 38. Giardiasis 39. Infection by MSRA 40. Infection by Naegleria 41. Ebola hemorrhagic fever 42. Anthrax 43. Mumps 44. Which group below has membrane biochemistry that is different from the other groups? A. Archeae B. Eubacteria C. algae or plant like protists D. animal like protists

8 45. What is the best way to prevent the spread of the agent that causes dengue fever? A. Frequent and proper hand washing. B. Making sure that all food is thoroughly cooked. C. Use of strong insect repellants D. Avoiding serving bagged lettuce and spinach 46. Suppose in 10 seconds a drug kills about 99.9% of the microbes present. Assume this rate is constant until all microbes are eliminated. If the cell population is originally 10 9, what will be the population be 20 seconds after exposure to the drug? ANSWER MUST BE EXPRESSED IN SCIENTIFIC NOTATION 47. Decreasing mosquito populations may result in a decrease of the incidence of all the following diseases except A. Rocky Mountain spotted fever B. Malaria C. Zika fever D. Yellow fever 48. Which of the following groups of organisms represent the main decomposers in the soil? A. bacteria and viruses C. fungi and viruses B. bacteria and fungi D. algae and fungi Match the following diseases with their usual mode of transmission. Each number will have only 1 answer. Some letters may be used more than once; others not at all. DISEASE MODE OF TRANSMISSION 49. pinworm A. Ingestion of contaminated food 50. influenza B. Inhalation 51. AIDS C. Animal bites 52. rabies D. Contact with sexual fluids 53. Lyme disease E. Answer not given Write the letter of the type of causative agent for each of the following diseases. Some answers may be used more than once; others not all. Each disease will have only 1 answer. Disease Causative Agent 54. Mononucleosis A. Fungus 55. Peptic ulcer B. Bacterium 56 Ringworm C. Prion 57. Chronic wasting disease D. Virus 57. Rubella E. Protozoan 58. Thrush F. Parasitic worm 59. Schistosomiasis G. Answer not given 60. Trichinosis 61. Rabies 62. Zika fever 63. Malaria 64. White nose syndrome 65. Tuberculosis 66. sickle cell anemia What is the ratio of the igloo circumference to its diameter? A: Eskimo pi

9 67-74 Match the letter for the type of microbe with the use/major characteristic. Some groups may be used more than one; others not at all. Each question will have only one letter as an answer. MAJOR USE TYPE OF MICROBE 67. Production of bread A. Eubacteria 68. Production of Yogurt B. Archeae 69. Production of much of world oxygen C. Fungi 70. Production of soy sauce D. Animal like protists 71. Assisting plants in capturing nitrogen E. Plant like protists 72. Moving genes into plants F. Answer not given 73. Production of toothpaste 74. Development of vaccine for polio 75. All of the following statements about biofilms are true except they A. May be involved in the introduction of invasive aquatic species by boat B. Are often responsible for the clogging of pipes C. May be involved in many food-borne illnesses D. Usually contain one type of microorganism. * 76. All of the following types of microbes may be composed of just one cell A. Eubacteria B. Pinworms. C. Algae D. Fungi 77. You wish to produce a 1/100 dilution. Which of the following methods will produce the desired dilution? A. Remove 1 ml from culture and add to 100 ml water. B. Remove 1 ml from culture and add to 9 ml water to make tube B. Remove 1 ml from tube B and add to 9 ml water to make tube C. C. Remove 1 ml from culture and add to 49 ml water to make tube B. Remove 1 ml from tube B and add to 49 ml water to make tube C. D. Remove 1 ml from culture and add to 74 ml water to make tube B. Remove 1 ml from tube B and add to 24 ml water to make tube C. 78. The number of bacteria in a culture can be determined in one of two ways: A. By making serial dilutions and then plating a small amount of the bacteria on a petri plate containing nutrients and agar B. By running a sample through an electronic cell counter. Which method, A or B, will produce the more accurate measurement of viable cells? 79. All of the following statements about diatoms are true except that they A. contain walls made of silica. B. produce > 20% of the world s oxygen supply as a result of photosynthesis C. are usually green in color D. contain a bipartite cell wall that consists of two overlapping halves How many evolutionists does it take to change a light bulb? A: Only one, but it takes eight million years.

10 80. You wish to develop an antibiotic that treats fungal infections with almost no effect on human cells. Which of the following mechanisms of the antibiotic will make the antibiotic effective only against fungal cells? A. Interference with cell wall synthesis. B. Interference with protein synthesis C. Interference with DNA replication D. Interference RNA synthesis 81. All of the following statements is true of pinworm infections EXCEPT A. It is caused by a worm that is usually >10 cm in length. B. The female lays eggs, usually at night, near the anal opening. C. The infection is common among school age children. D. One often gets the disease by swallowing eggs that may be on a contaminated finger. Q True/ False. Use the letters T or F to indicate if the statement is true or false. The letter MUST BE PRINTED AS A CAPITAL LETTER TO RECEIVE CREDIT. 82. If a person gets a disease once, he/she will be immune to getting the disease a second time. 83. The Archeae are limited in distribution and are found only in the soil. 84.The size of the cell is often helpful in determining the type of microbe that one is trying to identify. 85. Microbes can be used to help assist reduce trash that is in landfills. 86. Anti-fungal medicines are typically used to treat Cryptosporidiosis infections. 87.Bacterial and fungal infections can usually be treated with the same antibiotic. 88 Frequent, thorough hand washing is the best way of preventing the spread of disease that result from human contact 89. To bring an specimen into clear view when using a 40x objective, one should use both the course and fine focus knobs. 90.The soil microorganisms such as the bacteria, fungi, and roundworms determine the direction of ecosystem restoration. 91. Viruses contain only one type of nucleic acid, either DNA or RNA. 92. Prions typically are composed only of proteins. 93. Treatment of parasitic worm infections often requires chemicals that are not used to treat other types of infections. 94. Mitochondria, but not chloroplasts, contain DNA. 95. Cryptosporidiosis has emerged as the most frequently recognized cause of recreational water associated outbreaks of gastroenteritis. 96. The flagella of both bacteria and protozoans are composed of the same proteins.

11 97. Damaged sewage pipes often contain biofilms that consist of more than one microbe. 98. Some viruses are capable of inserting their nucleic acid into the DNA of the host cell. 99. You are hiking in the woods and discover some mushrooms. What is the type of microbe that you have found? A. virus B. fungus C. protozoan D. bacterium 100. Which of the following statements about lichens is true? A. They contain at least a fungus B. They contain at least a virus C. They contain at least a protozoan D. The contain at least a bacterium LeftBank: What the bank robbers did when their bag was full of money Heroes: What a man in a boat does Selfish: What the owner of a seafood store does

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13 Test Key: 2018 Boyceville Microbe B hrs 26. D 51. D 76. C /ml 27. D 52. C 77. B 3. 10/hr 28. A 53. C 78. A B 54. D 79. C hr 30. C 55. B 80. A hr 31. A 56. A 81.A B>D>>A>C 57. C 82.F 8. B /ml 58. A 83.F 9. 60x /ml 59. F 84. T x 35. B 60. F 85. T 11. 4x 36. D 61.D 86. F x10 4 um 37. G 62. D 87. F x10 4 um 38. E 63. E 88. T um 39.A 64. A 89. F um 40. F 65. B 90. T x10 2 um 41. C 66. G 91. T D 67.C 92. T 18. PROTOZOAN/ALGA 43.G 68. A 93. T 19. D 44. A 69. D 94. F 20. A 45. C 70. C 95. T 21. C C 96. F 22. B 47. A 72. F 97. T 23. D 48. B 73. E 98. T 24. C 49. E 74. F 99. B 25. A 50. B 75. D 100. A

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15 2017 Boyceville Invitational Microbe B Many of the comments on the C test apply to the B test as well. Some other specific comments. 1. Just because a calculation says organisms should fit in a field of view, what does a fraction of an organism look like? Answer should have been 4 critters. Numbers have meaning. Try to ask students what certain numbers mean. 2. Many olympiad events have time also as a criterion. Many tests are designed so that students working in unison will not finish the test or station. This last fact was certainly true with the B test. Many teams did not get beyond q 75. It is important to teach kids how to divide and conquer. Students should decide how questions will be divided. If one finishes the part, this person can then check the others answers etc. 3. I want to reemphasize metric conversions. This task will appear in many different aspects of SO and life in general. Start with the basics. Make sure kids understand metric prefices. Converting from a smaller unit to a larger unit will result in a smaller final number : 320 mm = 0.32 m. Converting from a larger unit to a smaller unit will yield a larger number: 1 m = 1000 mm. There are lots of problems using the factor-labeling system floating around. It is important to get students to use units in their calculations. 4. Spend some time getting students to understand the use of scales. Many teams arrived at the incorrect order of size for q Students should not only know the type of agent that causes a disease on the national list, they should also be able to recognize at least some of the critters. Most people writing this test will have some pictures of different causative agents. This statement reflects the statement in the rules that students should be able to distinguish different bacterial shapes. I am not saying students should try to memorize the shapes of all the agents, but they should have a general few of at least classes of microbes. 6. Students need to be aware of procaryotic and eucaryotic cell structures/organelles and their differences. 7. One can/should usually expect a couple questions dealing with similarity of mitochondria/ chloroplasts to eubacteria. 8. Students need to be aware of the type of microbial agent that causes various diseases. Along this line, they should know that each class of agents usually requires a different mode of treatment