MCB 2010 Lab Study guide 1
10. Everything going into the incubator must be labeled with name, microbial content and other data, using black marking tools. A. TRUE B. FALSE
A
102. A stain and mordant react with the flagella, increasing its diameter to allow viewing in the microscope. A. TRUE B. FALSE
A
104. Endospores provide a resistant form for survival of the organism in unfavorable conditions. A. TRUE B. FALSE
A
106. A special staining technique must be used to drive dye into endospores. A. TRUE B. FALSE
A
107. Usually malachite green is heated to stain the endospores, and then the vegetative bacteria are counterstained with safranin. A. TRUE B. FALSE
A
109. Boiling water is used in the process of staining an endospore A. TRUE B. FALSE
A
110. 15-20 minutes of steam is used in the process of staining an endospore A. TRUE B. FALSE
A
112. During the process of staining an endospore, running water washes the green stain out of the vegetative cells and sporangia, and they become colorless. A. TRUE B. FALSE
A
113. The counterstain then dyes the vegetative cells red. A. TRUE B. FALSE
A
121. The science of taxonomy provides us with a system for classifying and naming organisms. A. TRUE B. FALSE
A
123. Domains Archaea and Bacteria contain all organisms with cells that are prokaryotic A. TRUE B. FALSE
A
126. Within each of the domains, a hierarchical taxonomic system places similar similar genera into the same family A. TRUE B. FALSE
A
127. Within each of the domains, a hierarchical taxonomic system places similar similar families into the same order A. TRUE B. FALSE
A
128. Within each of the domains, a hierarchical taxonomic system places similar similar orders into the same class A. TRUE B. FALSE
A
129. Within each of the domains, a hierarchical taxonomic system places similar and similar classes into the same phylum A. TRUE B. FALSE
A
133. Firmicutes and Actinobacteria differ from each other in the percentage of Guanine and Cytosine (G + C) bases (relative to Adenine and Thymine) in their DNA. A. TRUE B. FALSE
A
134. Firmicutes contains five key genera A. TRUE B. FALSE
A
136. Actinobacteria contains two key genera including Mycobacterium and Streptomyces A. TRUE B. FALSE
A
139. Proteobacteria contains five key genera: Escherichia, Pseudomonas, Rhizobium, Salmonella, and Spirillum. A. TRUE B. FALSE
A
140. The members of phylum Cyanobacteria, including the ke genus Anabaena, are unique in their metabolic strategy, utilizing oxygenic photosynthesis to obtain energy and organic carbon molecules. A. TRUE B. FALSE
A
141. Many of the Cyanobacteria also use nitrogen fixation (in specialized cells called heterocysts) to convert gaseous nitrogen into a form they can use A. TRUE B. FALSE
A
149. Phylum Cyanobacteria contains genera Anabaena which utilizes heterocysts for nitrogen-fixation A. TRUE B. FALSE
A
151. When looking at a slide of Wasserblüthe, you will observe many different types of Cyanobacteria.' A. TRUE B. FALSE
A
154. Firmicutes have a low G + C content in DNA A. TRUE B. FALSE
A
158. Congo red and India ink are ____stains A. negative B. neutral C. basic D. positive E. C and D
A
160. Bacillus sp. is a rod shaped microbe that divides only along 1 axis A. TRUE B. FALSE
A
166. The two commonly used methods to determine if a bacterium is motile are wet-mount preparation (microscopic) and motility media (mac-roscopic) A. TRUE B. FALSE
A
168. 0.005% triphenyltetrazolium chloride (TTC) TTC can be utilized by bacteria as an electron acceptor and in its reduced form turns red. A. TRUE B. FALSE
A
171. Bacteria have rigid cell walls that function to maintain a constant shape. A. TRUE B. FALSE
A
175. Old cultures tend to decolorize more easily than younger cultures. A. TRUE B. FALSE
A
176. The acid fast stain receives its name because certain bacteria, particularly the Mycobacteria, have a tendency to resist decolorization by acids. A. TRUE B. FALSE
A
177. Gram stained Mycobacteria appear blue/purple A. TRUE B. FALSE
A
178. Acid fast organisms have a high content of fat or lipid and mycolic acids in their cell walls. A. TRUE B. FALSE
A
179. Two types of acid fast stains include Ziehl-Neelsen (Z-N) and Method Kinyon Method A. TRUE B. FALSE
A
18. Flame inoculating tools using the Bunsen burner until they are red hot in order to sterilize A. TRUE B. FALSE
A
182. Ethanol is thought to extract the lipid from the gram-negative cell wall and dehydrate the cell wall of the gram-positive organism A. TRUE B. FALSE
A
2. All of the organisms we work with should be handled as if they are pathogenic A. TRUE B. FALSE
A
21. Contents of tubes will spill if you lay the tube on the table or invert it A. TRUE B. FALSE
A
22. Hold the tube in your nondominant hand (right-handed people should hold the tube in their left hand) and the inoculating loop in your dominant hand. A. TRUE B. FALSE
A
23. When handling a petri dish with agar tilt the lid up to open it, do not completely remove it A. TRUE B. FALSE
A
24. Airborne microorganisms can contaminate sterile media and inoculating tools A. TRUE B. FALSE
A
27. Define ubiquitous A. Present everywhere B. Present nowhere C. All of the above D. None of the above
A
29. Cultural characteristics include size, form, margin, elevation, opacity, color A. TRUE B. FALSE
A
3. All of the organisms we work with should be handled as if they are opportunistic A. TRUE B. FALSE
A
30. One of the most important steps in identifying a new bacteria or one isolated from a patient's specimen is noting colony morphology A. TRUE B. FALSE
A
31. Colony morphology is described as how the colony or clone of cells looks on the agar surface. A. TRUE B. FALSE
A
34. Nutrients present in various media or incubation conditions may contribute to altered colony size or appearance. A. TRUE B. FALSE
A
35. Increased or specific carbohydrate content may result in more pronounced bacterial capsule synthesis, leading to very mucoid colonies. A. TRUE B. FALSE
A
36. Some temperatures may be restrictive or stimulating to growth of specific species. A. TRUE B. FALSE
A
41. Mycoplasma are pleomorphic because they have no cell wall. A. TRUE B. FALSE
A
42. Mycoplasmas can be opportunistic pathogens. A. TRUE B. FALSE
A
43. Mycoplasmas can pass through sterilizing filters, and do not stain with ordinary stains. A. TRUE B. FALSE
A
48. Rickettsiae are very small bacteria that can only grow and multiply intracellularly, as they are obligate parasites. A. TRUE B. FALSE
A
50. Rickettsiae must be grown in cell culture or intact animals. A. TRUE B. FALSE
A
52. Pathogenic Rickettsiae include the causative agents for typhus and Rocky Mountain spotted fever. A. TRUE B. FALSE
A
55. Chlamydiae must grow and multiply inside another cell; then they are released to infect new cells. A. TRUE B. FALSE
A
56. There are two species of Chlamydiae responsible for human disease: psittaci (parrot fever) and trachomatis (STD, trachoma, LGV). A. TRUE B. FALSE
A
57. Psittaci and trachomatis can only be studied in cultured cells or intact animals A. TRUE B. FALSE
A
60. Both the media and the colonies may be colored if the bacteria produces an intracellular pigment and an extracellular pigment A. TRUE B. FALSE
A
61. There are different degrees of opacity. A. TRUE B. FALSE
A
64. Size distinctions to be made include pinpoint, small, medium, and large. A. TRUE B. FALSE
A
65. In colony morphology, 'margin' refers to what the edge of the colony looks like A. TRUE B. FALSE
A
69. To observe opacity, hold the plate obliquely to the overhead light or place the plate over the writing of your textbook/notebook/handout. A. TRUE B. FALSE
A
7. Inoculation loops and needles are flamed before and after use. A. TRUE B. FALSE
A
70. Transparent colonies allow all of the light to pass through them. A. TRUE B. FALSE
A
71. Translucent colonies allow most of the light to pass through them; some light is blocked. A. TRUE B. FALSE
A
73. If the bacteria produce an intracellular pigment that is retained by the cell, the colony becomes colored. A. TRUE B. FALSE
A
74. If the bacteria produce an extracellular pigment that is excreted by the cell, the medium becomes colored. A. TRUE B. FALSE
A
75. If the organisms are translucent, the colored media will show through the colonies, and the colonies will appear to have the same color as the media. A. TRUE B. FALSE
A
78. Special stains are available for characteristic surface or internal components as well as for other cell components to aid in the study of microbes. A. TRUE B. FALSE
A
79. The acid-fast stain is a differential stain for Mycobacterium and related bacteria. A. TRUE B. FALSE
A
8. Aerosols created by splattering of cultures are caused by improper flaming and cooling of needles and loops before use. A. TRUE B. FALSE
A
80. Mycobacterium is a genus that includes the causative ages of leprosy and tuberculosis A. TRUE B. FALSE
A
81. It is useful clinically to have a stain for rapid identification of Mycobacterium in sputum or skin scrapings. A. TRUE B. FALSE
A
82. Mycobacterium are unusual in that the cell wall has a mixture of waxy lipids called mycolic acids, that prevent the bacterium from staining by simple and gram stains. A. TRUE B. FALSE
A
85. A stain that is cooked into the waxy cell wall, and cannot be removed with acidified alcohol is acid-fast. A. TRUE B. FALSE
A
86. Non acid fast bacterium and tissue background will lose the carbolfuchsin stain when washed with acid-alcohol, becoming colorless. A. TRUE B. FALSE
A
87. A counterstain (methylene blue) is used to see them non acid fast bacterium A. TRUE B. FALSE
A
88. The genus Mycobacterium contains some pathogens and many saprophytic species, found in soil and water, and also on human skin and mucous membranes. A. TRUE B. FALSE
A
9. The mouth of test tubes and other culture vessels are to be flamed before use A. TRUE B. FALSE
A
91. Acid-fast stain is important for quick diagnosis because some strains of Mycobacterium, such as M. leprae, cannot yet be grown in culture. A. TRUE B. FALSE
A
92. Capsules are found on some bacteria (and fungi) A. TRUE B. FALSE
A
93. Capsules may actually relate to pathogenicity in some strains, such as Streptococcus pneumoniae, Klebsiella pneumoniae, and Clostridium perfringens. A. TRUE B. FALSE
A
96. In a negative stain technique, material such as India ink or Congo red is used to coat the slide but not penetrate the cell or capsule A. TRUE B. FALSE
A
97. A stain can be used to color the cells, and then the capsule is seen as a clear region surrounding the cells against the dark background. A. TRUE B. FALSE
A
98. There are direct and indirect methods of staining capsules. A. TRUE B. FALSE
A
Exercise 5.4 173. The most common clinically used methods of differential staining are the Gram stain and the Acid-fast stain. A. TRUE B. FALSE
A
Exercise 5.9 180. The correct order of the gram stain procedure is: A. crystal violet-iodine-ethanol-safranin B. safranin-crystal violet-iodine-ethanol C. iodine-safranin-crystal violet-ethanol D. crystal violet-ethanol-iodine-safranin E. crystalviolet-iodine-safranin-ethanol
A
Exercise 6.3 169. The purpose of making a smear is to adhere/fix the bacteria to the slide to prevent the sample from being lost during the staining process. When using a liquid culture, one loopful of culture is smeared onto a glass slide and allowed to air dry. The cells in the dried smear are then "fixed" to the slide by briefly heating. This process is known as heat fixation. A. TRUE B. FALSE
A
1. All of the organisms we work with are pathogenic A. TRUE B. FALSE
B
100. Flagella have a carbohydrate structure requiring a special staining technique A. TRUE B. FALSE
B
103. Endospore formation is most characteristic of two genera of bacteria, Bacillus and Mycobacterium A. TRUE B. FALSE
B
105. Because of the weak spore coating, they are not readily stained and may appear as empty "holes" in simple or gram-stained bacteria. A. TRUE B. FALSE
B
108. Endospores appear blue in red bacterial cells. A. TRUE B. FALSE
B
11. Non-contaminated waste goes into the autoclavable bags. Contaminated disposable waste goes into the waste basket. A. TRUE B. FALSE
B
111. Cooking safranin into the resistant endospore wall is used in the process of staining an endospore A. TRUE B. FALSE
B
114. Vegetative cells are dormant A. TRUE B. FALSE
B
115. Endospores are reproductive germinating cells A. TRUE B. FALSE
B
12. Never lay tubed media down vertically, at anytime—it will spill. A. TRUE B. FALSE
B
122. The currently accepted taxonomic system places all organisms into one of five Domains: Eukarya, Archaea, Bacteria, Fungi, Animalia A. TRUE B. FALSE
B
124. Prokaryotic cells have chromosomes that are contained in a true membrane-bound nucleus. A. TRUE B. FALSE
B
125. Within each of the domains, a hierarchical taxonomic system places similar species into the same kingdom A. TRUE B. FALSE
B
13. Aseptic techniques are any techniques employed to encourage contamination. A. TRUE B. FALSE
B
130. There are seven phyla of the Domain Bacteria. A. TRUE B. FALSE
B
132. Firmicutes and Actinobacteria are generally Gram negative A. TRUE B. FALSE
B
138. Chlamydiae has the most genera (> 300) of any other bacterial phylum A. TRUE B. FALSE
B
142. Rhizobium of the Proteobacteria use carbon fixation (in specialized cells called heterocysts) to convert gaseous carbon dioxide into a form they can use. A. TRUE B. FALSE
B
143. Phylum Chlamydiae is unique among bacteria in that its members have an abundance of peptidoglycan in their cell walls A. TRUE B. FALSE
B
144. Phylum Chlamydiae bacteria do not have genes for production of peptidoglycan. A. TRUE B. FALSE
B
145. There are no disease-causing species of the genus Chlamydia A. TRUE B. FALSE
B
147. Escherichia, Pseudomonas, Rhizobium, Salmonella and Spirillum are genera of: A. Actinobacteria B. Proteobacteria C. Cyanobacteria D. Streptomyces E. Firmicutes
B
15. An axenic culture is a mixed culture of organism of interest. A. TRUE B. FALSE
B
150. Wasserblüthe is a German word meaning 'water fall" A. TRUE B. FALSE
B
152. The dominant metabolic strategy of all five major phyla in the domain bacteria is oxygenic photosynthesis A. TRUE B. FALSE
B
153. Actinobacteria have a low G + C content in DNA A. TRUE B. FALSE
B
157. Bacterial cells have a positive charge A. TRUE B. FALSE
B
159. Staphylococcus sp. is arranged as chains and is rod shaped A. TRUE B. FALSE
B
16. Typically growth media is sterilized by flaming A. TRUE B. FALSE
B
167. Brownian motion is the ordered moving of particles resulting from their collisions with atoms or molecules in the water. A. TRUE B. FALSE
B
17. An autoclave sterilizes by using halogenated gases A. TRUE B. FALSE
B
170. When using growth from an agar medium to make a smear, a loopful of water is placed on the slide, and a very large amount of culture is mixed with the water to separate and suspend the bacteria. The suspension is then spread out, air dried, and heat fixed. In a good smear, the bacteria are evenly spread out on the slide and individual organisms are visible microscopically. A. TRUE B. FALSE
B
172. There are five basic bacterial shapes: cocci, bacilli, rectangle, star and spiral. A. TRUE B. FALSE
B
181. Crystal violet is used as the primary stain in the gram stain procedure because it contains an anionic ion that binds to the cell wall of both gram-positive and gram negative cells because the cell walls of both are negatively charged. A. TRUE B. FALSE
B
19. Blow on the sterilized inoculating tools to cool them A. TRUE B. FALSE
B
20. Test tubes are fitted with loose caps that will not come off, so you can hold the tube by the cap A. TRUE B. FALSE
B
25. Most bacterial cultures will be incubated at 55°C for 24 to 48 hours A. TRUE B. FALSE
B
33. Colony morphology does not vary with microbial growth conditions A. TRUE B. FALSE
B
37. Mycobacterium, Mycoplasma, Chlamydia, and Rickettsia are not pathogens A. TRUE B. FALSE
B
38. Species of Rickettsia can cause pneumonia, urogenital and other infections and are normally found in normal mucous membrane microflora A. TRUE B. FALSE
B
39. Mycobacterium, Mycoplasma, Chlamydia, and Rickettsia are not classified as true bacteria A. TRUE B. FALSE
B
4. Wash hands with disinfectant and wipe bench tops with soap and warm water before starting any lab exercise and after all work has been completed. A. TRUE B. FALSE
B
40. Mycobacterium, Mycoplasma, Chlamydia, and Rickettsia are extremely large and cannot be cultured by ordinary methods. A. TRUE B. FALSE
B
44. Mycoplasmas are susceptible to the antibiotics which act by inhibiting cell wall synthesis. A. TRUE B. FALSE
B
49. Rickettsiae have a cell wall that cannot be stained. A. TRUE B. FALSE
B
51. Most Rickettsiae are transmitted by arthropods like bats A. TRUE B. FALSE
B
53. Chlamydiae are motile, coccoid, obligate intracellular parasites. A. TRUE B. FALSE
B
54. Chlamydiae have three life forms, or stages, known as the elementary body, primary body and the reticulate body. A. TRUE B. FALSE
B
59. If the organism produces an extracellular pigment the media turns colorless A. TRUE B. FALSE
B
6. In the lab long hair must be tied back and loose clothing should be worn A. TRUE B. FALSE
B
62. In colony morphology, 'size' relates to the size of the bacterial cell A. TRUE B. FALSE
B
63. To examine size, observe colonies in the most densely populated quadrant of the plate (e.g., first quadrant) A. TRUE B. FALSE
B
66. To observe elevation, it is best to look at the bottom of your plate A. TRUE B. FALSE
B
67. To observe elevation, it is best to look at the top of your plate A. TRUE B. FALSE
B
68. In colony morphology, 'transparency' is how much light is able to pass through the colony. A. TRUE B. FALSE
B
72. Opaque colonies block none of the light. A. TRUE B. FALSE
B
76. White colonies or translucent colonies that take on the color of the straw-colored media are termed "pigmented" A. TRUE B. FALSE
B
83. Fatty lipids called mycolic acids also prevent drying of the microbe. A. TRUE B. FALSE
B
84. In the acid-fast stain, a green stain (carbolfuchsin) is cooked into the waxy cell wall, and cannot be removed with acidified alcohol. A. TRUE B. FALSE
B
89. Mycobacterium grows very fast in the laboratory on a complex media. A. TRUE B. FALSE
B
90. Often it will take 9 weeks for visible growth of Mycobacterium in culture. A. TRUE B. FALSE
B
94. Small capsules can protect the microbe from host defense mechanisms, especially phagocytosis. A. TRUE B. FALSE
B
95. Capsules are often identified immunologically, but can also be visualized with a simple gram stain. A. TRUE B. FALSE
B
99. Flagella are tiny hairlike organelles for pathogenicity. A. TRUE B. FALSE
B
Exercise 5.3 161. A/an ______ is a small glass disc with uniformly spaced lines etched on it. A. microscope B. ocular micrometer C. stage D. objective E. binocular
B
Exercise 6.5 58. Microbial colonies can be colored/pigmented because of loss of nutrients and carbohydrates to the growth media A. TRUE B. FALSE
B
32. Colony morphology is identical between various microbial species A. TRUE B. FALSE
BB
116. What is the clinical value of an acid-fast stain? A. Rapid identification of Clostridium B. Rapid identification of Bacillus C. Rapid identification of Mycobacterium D. All of the above E. None of the above
C
119. Why must the spore stain include a heating step? A. Cooking safranin into the resistant endospore allows its visualization B. Cooking congo red into the resistant endospore allows its visualization C. Cooking malachite green into the resistant endospore allows its visualization D. Cooking malachite green into the resistant endospore prevents its visualization E. None of the above
C
146. Mycobacterium and Streptomyces are genera of: A. Cyanobacteria B. Proteobacteria C. Actinobacteria D. Streptomyces E. Firmicutes
C
28. Characteristics of a pure culture include: A. All colonies have the same textures B. All colonies have different margins C. All colonies have the same elevations D. All colonies have different pigment E. None of the above
C
117. Why is a capsule stain useful in the lab? A. To identify bacterium with a flagella B. To identify bacterium with an endospore C. Because encapsulated bacteria cannot be stained D. To identify whether or not a bacterium has a capsule E. None of the above
D
137. Gram-negative phyla include A. Proteobacteria B. Cyanobacteria C. Chlamydiae D. All of the above E. A and B
D
162. The smallest object you can possibly see (as a barely-visible dot under the oil-immersion lens) with a light microscope is about ____ A. 0.1 μm B. 0.4 μm C. 2 μm D. 0.2 μm E. 0.3 μm
D
165. The following is/are methods to examine flagella provide motility to the cell. A. negative stain B. electron microscopy C. Ryu stain D. B and C E. A, B, and C
D
174. What is true of gram negative organisms A. stain blue/purple B. have thick peptidoglycan C. do not have an outer membrane D. clear when decolorized E. none of the above
D
45. A type of colony morphology form includes A. Raised B. Convex C. Flat D. FILAMENTOUS E. UMBONATE
D
46. A type of colony morphology margin includes A. Raised B. Convex C. Flat D. FILAMENTOUS E. UMBONATE
D
47. Types of colony morphology elevation include A. Crateriform B. Umbonate C. Flat D. All of the above E. None of the above
D
Exercise 4.2 77. Characteristic surface or internal components that are of value in identifying organisms include: A. Endospores B. Capsules C. Flagella D. All of the above E. None of the above
D
The 2 gram positive microorganisms
M luteus and S aureus
Exercise 6.1 163. E. binocular A. 0.1 μm B. 0.4 μm C. 2 μm D. 0.2 μm E. 0.3 μm
NO
The 3 gram negative microorganisms
P fluor, S. Marcescens, E. coli
101. The number of flagella and their arrangement can be defined as: A. Monotrichous B. Amphitrichous C. Lophotrichous D. Peritrichous E. All of the above
E
118. What is the importance of the different arrangements of flagella? A. Pathogenicity B. Attachment C. Speed D. Virulence E. Locomotion
E
120. What would happen if the heating step were omitted from the spore stain? A. The endospore would be green B. The endospore would be blue C. The endospore would be black D. The endospore would be red E. The endospore would be clear
E
131. Firmicutes and Actinobacteria are two bacterial A. Families B. Genera C. Classes D. Orders E. Phyla
E
135. Bacillus, Clostridium, Lactobacillus, Staphylococcus and Streptococcus are genera of: A. Actinobacteria B. Proteobacteria C. Cyanobacteria D. Streptomyces E. Firmicutes
E
14. Methods to prevent contamination include: A. flaming B. autoclaving C. sterilizing D. use of steam under pressure E. all of the above
E
148. Which phylums have one genera? A. Cyanobacteria B. Chlamydiae C. Anabaena D. None of the above E. A and B
E
156. The following is a bacterial stain A. safranin B. methylene blue C. crystal violet D. malachite green E. All of the above
E
26. Define colony: A. Macroscopic bacterial growth on solid media B. Microorganisms all originating from a single mother cell C. Bacterial clones D. Genetically identical bacteria E. All of the above
E
5. The following are not allowed in the lab: A. food B. drink C. children D. smoking E. All of the above
E
Exercise 5.2 155. Crystal violet is a ______ stain. A. negative B. neutral C. basic D. positive E. C and D
E
Exercise 6.2 164. _____ is/are bacterial flagellar arrangements that are polar A. monotrichous B. amphitrichous C. lophotrichous D. peritrichous E. A, B, and C
E
