Test Practice Questions to Study for Microbiology Chapter Four Part 1

Test Bank Multiple Choice Questions 1. E. coli has been isolated and cultured from three different individuals. Upon biochemical testing of these three cultures, you find that there are differences in some reactions. What is the best explanation of these differences? A. B. C. D. E. 2. These represent three different species of E. coli. This is normal genetic variation seen among strains of E. coli. Two of the cultures are mutants of the other. The other two cultures are not really E. coli. Mistakes have been made in the test interpretation. In which situation would a bacterium most likely have cytoplasmic inclusions? A. B. C. D. When producing an endospore When the cell is synthesizing flagella When the cell is starved for nutrients In a habitat abundant in nutrients True / False Questions 3. If you observe rod-shaped, pink cells on a slide that had just been Gram stained, you can assume that their cell envelope contains endotoxin. True False 2-20-13 Multiple Choice Questions 4. You apply the acid-fast stain method to a patient's specimen, an aspirate from the lungs. Microscopic examination reveals a large number of bright pink-red bacillus-shaped bacteria in the smear. Which statement is true? A. B. C. D. 5. A patient has a serious respiratory infection. A sputum sample yielded a bacterium that did not have any peptidoglycan. You hypothesize that the identity of this microbe could possibly be ______. A. B. C. D. E. 6. This is the expected outcome for normal sputum. The patient has pneumonia. The patient has tuberculosis. The patient has an HIV infection. Streptococcus pneumoniae Mycobacterium tuberculosis Borrelia burgdorferi Staphylococcus aureus Mycoplasma pneumoniae You have made a smear of a bacterial culture and have performed the Gram stain on it. Looking at the organism under the microscope, you notice that the cells do not seem to be the dark blue-purple of a gram-positive reaction, but instead are light purple. Your staining procedure was performed correctly. What is your best explanation as to why the bacteria have stained this way? A. The bacteria were taken from an inappropriate medium, and a chemical is interfering with proper staining of the cells. B. There is something in the wall of the bacteria that has affected the uptake of the crystal violet into the cell wall, thereby staining it improperly. C. The specimen did not undergo heat fixation before staining; therefore, the primary dye does not stick properly to the wall. E. These are mutant bacteria which cannot be stained like other bacteria. 7. You have found a mutant of Streptococcus pneumoniae that has lost the ability to produce a capsule. If you inject this strain into a population of healthy mice, what prediction can you make about the consequences? A. B. C. D. 8. You've just isolated a new bacterium in pure culture, and you culture it on a general purpose medium where its cells have a coccobacillus morphology. When you examine the cells after culturing on a variety of differential media, you find that in some cases, the cells appear as coccobacillus, but in others, they can be filamentous, cocci, or club-shaped. The best explanation for this observation is that A. B. C. D. E. 9. The mice will get a severe case of pneumonia and recover. The mice will remain healthy. The mice will die of pneumonia. The infection will respond to antiviral medication. the media were incubated at an incorrect temperature. the differential media are contaminated. the microscope is out of adjustment. the bacterium is pleomorphic. your culture has become contaminated. You've just isolated a new bacterium in pure culture, and you culture it on a general purpose medium where its cells have a rod-shape (bacillus) morphology. In addition to culturing it on solid media, you inoculate a slide to grow it as a biofilm. When you use confocal microscopy to image the biofilm, you observe that there are several cellular morphologies, ranging from coccus to coccobacillus to long bacillus. The best explanation for this observation is that A. B. C. D. the confocal microscope is out of adjustment. the biofilm is no longer a pure culture of the microbe. the biofilm culture was not incubated under the appropriate conditions. the microenvironments within a biofilm promote structural variation. 10. A new drug is found to act by blocking the incorporation of subunits into sterol molecules for the cell membrane. Which statement is true? A. B. C. D. E. Only archaeal cells would be affected by this drug. Only biofilms would be affected by this drug. Most bacteria would be unaffected by this drug. A drug with this mechanism would be an excellent antibiotic. This kind of drug would destroy viruses only. 11. You need to determine if a pure culture of bacteria is gram-positive or gram-negative, but you've just spilled your only solution of crystal violet so you can't do a Gram stain. You decide to try a lysozyme treatment on a sample of each culture and then examine the samples under the microscope. The expected result is A. gram-positives will lyse and appears as debris; gram-negatives will lyse but more slowly. B. gram-positives will lyse and appears as debris; gram-negatives will be unaffected. C. gram-positives will lyse and appears as debris; gram-negatives will lose cellular morphology and appear as cocci. D. gram-negatives will lyse and appears as debris; gram-positives will lose cellular morphology and appear as cocci. E. gram-negatives will lyse and appears as debris; gram-positives will be unaffected. 12. Researchers studying the rigidity and flexibility of the cell envelope used chemotaxis to measure the ability of microbes to squeeze through tight spaces. E. coli, a gram-negative bacterium, was able to traverse narrower channels than B. subtilis, a gram-positive microbe, even though both cells are the same size when grown without restriction. E. coli has the more flexible cell envelope because A. B. C. D. E. lipopolysaccharide has no charge. it has fewer flagella. it has only a single membrane. there is less structural carbohydrate. there are fewer protein receptors. 13. The process of sporangium formation and endospore maturation requires 6-8 hours. What is most likely to result if the temperature of the environment was raised to 100°C about 2 hours after the process started? A. B. C. D. E. The chromosome in the endospore would likely carry mutations. The endospore would form more slowly and be heat resistant. The endospore would form properly but would be unable to germinate. The organism would be termed a hyperthermophile. The endospore would not form properly because it is not yet heat resistant. 14. Archaea have been found in many microenvironments in the human body. Which of the following microenvironments is most likely to fit with the designation of Archaea as "extremophiles?" A. B. C. D. The inner ear can withstand increased pressure. The surface of the tongue has salt receptors. The gingiva and the gut are anaerobic. The temperature of the testes is less than 37°C. 15. At present, the most accurate indicator of evolutionary relatedness among organisms is the A. B. C. D. E. size of the bacterial chromosome. similarities of cell membrane proteins. sequence of the ribosomal small subunit RNA. size of the ribosomes. size of the periplasmic space. 16. Serological analysis for bacterial identification typically involves using A. B. C. D. E. specific antibodies to the bacterial cell antigens. a microscope to determine cell morphology. the determination of guanine + cytosine base concentrations. methods to identify cell enzymes. the analysis of the appearance of colonies. 17. Which of the following bacteria is not closely related to the others? A. B. C. D. Salmonella enterica subsp. enterica Salmonella enterica subsp. indica Salmonella bongori Salmonella enterica subsp. arizonae 18. Which of the following is mismatched? A. B. C. D. Tenericutes - waxy, acid-fast cell walls Gracilicutes - gram-negative cell walls Mendosicutes - archaea cell walls Firmicutes - gram-positive cell walls 19. A research laboratory that identifies the subspecies of bacterial isolates from a recent Salmonella epidemic would refer to Bergey's Manual of ______ Bacteriology for guidance in identification. A. B. C. D. Systematic Classical Evolutionary Determinative 20. A clinical laboratory that identifies the bacterial agents that cause human disease would refer to Bergey's Manual of______ Bacteriology for guidance in identification. A. B. C. D. Systematic Determinative Classical Evolutionary 21. The reference for bacterial descriptions and classifications is _____ Manual of Systematic Bacteriology. A. B. C. D. E. Leeuwenhoek's Lister's Koch's Bergey's Pasteur's 22. Which of the following is not a phenotypic trait of bacteria? A. Cell shape B. Biochemical reactions C. rRNA sequence D. Nutrient requirements True / False Questions 23. Archaea do not have the typical peptidogly can structure found in bacterial cell walls. True False Multiple Choice Questions 24. Which of the following is mismatched? A. B. C. D. E. Psychrophiles - adapted to very low temperatures Extreme halophiles - adapted to salty habitats Methanogens - convert CO2 and H2 into methane Hyperthermophiles - adapted to high temperatures Thermoplasmas - adapted to warm-blooded animal environments 25. Halobacterium salinarum lives in and requires a high salt concentration. This is an example of an archaeon described as a ______. A. B. C. D. barophile halophile thermophile psychrophile 26. The function of bacterial endospores is A. B. C. D. to provide a protected site for photosynthesis. storage of excess cellular building blocks. protection of genetic material during harsh conditions. reproduction and growth. 27. Chemical analysis of a bacterial cell detects dipicolinic acid. What is the identity of this structure? A. B. C. D. E. Nucleoid Cell wall Biofilm Capsule Endospore 28. Endospores are A. B. C. D. E. metabolically inactive. resistant to heat and chemical treatments. resistant to destruction by radiation. living structures. All of the choices are correct. 29. Bacterial endospores are produced by ______. A. B. C. D. Entamoeba Bacillus Mycoplasma Staphylococcus 30. All of the following occur during endospore germination except A. B. C. D. the cell grows out of its protein coats. binding of a small organic molecule to initiate germination. dehydration of the cell components. enzymes digest the endospore cortex. 31. All of the following structures contribute to the ability of pathogenic bacteria to cause disease except ______. A. B. C. D. E. gram-negative outer membrane inclusions slime layer capsule fimbriae 32. Magnetosomes are A. B. C. D. E. infoldings of the cell membrane. found in all bacteria and some archaea. responsible for the heat resistance of endospores. also termed metachromatic granules. composed of magnetic iron oxide particles. 33. Plasmids A. B. C. D. E. are found in all bacteria. are essential for survival. are located in microcompartments. cannot be passed between organisms. often carry genes controlling pathogenicity. True / False Questions 34. Endospores of certain bacterial species can enter tissues in the human body, germinate, and cause an infectious disease. True False 35. Boiling water (100°C) can normally destroy endospores. True False Multiple Choice Questions 36. All bacterial cells have ______. A. B. C. D. E. an S-layer flagella the ability to produce endospores capsules a chromosome 37. Which of the following bacterial structures is incorrectly matched with a function? A. B. C. D. E. Nucleoid - hereditary material Plasmids - contain genes essential for growth and metabolism Cytoplasm - dense, gelatinous solution Ribosomes - protein synthesis Inclusions - excess cell nutrients and materials 38. The site for ATP synthesis in bacterial cells is the ______. A. B. C. D. E. cell membrane mitochondrion cell wall microcompartment ribosome 39. The most immediate result of destruction of a cell's ribosomes would be that A. B. C. D. E. material would not cross the cell membrane. the chromosome would unravel. protein synthesis would stop. holes would appear in the capsule. glycogen inclusions would form. 40. The chromosome in bacteria and archaea A. B. C. D. contains all the cell's plasmids. is located in the cell membrane. forms a single linear strand of DNA. is part of the nucleoid. 41. The chemical components of ribosomes are proteins and ______. A. B. C. D. mRNA tRNA rRNA DNA True / False Questions 42. Some bacteria have a cytoskeleton of sterols to help maintain their shape. True False Multiple Choice Questions 43. A bacterial genus that has waxy mycolic acid in the cell walls is ______. A. Bacillus B. Mycobacterium C. Mycoplasma D. Corynebacterium. E. Streptococcus 44. Mycobacterium and Nocardia are different from most gram-positive bacteria in that their cell walls A. B. C. D. contain a layer of lipopolysaccharide. contain more peptidoglycan. are easily decolorized during staining. contain unique, waxy lipids. 45. Which of the following does not pertain to endotoxin? A. B. C. D. Endotoxin can cause septic shock in the human body. Endotoxin is found in acid-fast bacterial cell walls. Endotoxin can stimulate fever in the human body. Endotoxin is a bacterial cell wall lipid. 46. Lipopolysaccharide is an important cell envelope component of ______.: 01_2015_CS-969 A. B. C. D. E. acid-fast bacteria gram-positive bacteria gram-negative bacteria mycoplasmas protoplasts 47. Which of the following is not true of the outer membrane? A. B. C. D. E. The uppermost layer is made of lipopolysaccharide. The lipid portion of the lipopolysaccharide layer is termed endotoxin. Gram-positive bacteria have an outer membrane. The innermost layer is a phospholipid bilayer. Porins create channels through the outer membrane. True / False Questions 48. The cell envelope or its parts can interact with human tissue and cause disease. True False Multiple Choice Questions 49. Peptidoglycan is a unique macromolecule found in bacterial ______. A. B. C. D. E. slime layers capsules cell walls cell membranes inclusions 50. A bacterial cell wall that has primarily peptidoglycan with small amounts of teichoic acid and lipoteichoic acid is ______. A. B. C. D. a spheroplast acid-fast gram-negative gram-positive E. a protoplast 51. The macromolecule containing alternating N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM) chains cross-linked by short peptide fragments is ______. A. B. C. D. E. lysozyme lipopolysaccharide mycolic acid peptidoglycan teichoic acid 52. Gram-negative bacteria: 07_28_2014_QC_51843 A. B. C. D. have a more complex cell envelope with a greater variation in chemical composition. appear purple following the Gram stain. are generally more susceptible to antibiotics than gram-positive bacteria. include all pathogens. 53. If bacteria living in salty seawater were displaced to a freshwater environment, the cell structure that would prevent the cells from rupturing is the ______. A. B. C. D. E. slime layer capsule endospore cell membrane cell wall 54. The outcome of the Gram stain is based on differences in the ______. A. B. C. D. cell membrane flagella cell wall ribosomes 55. Which is the correct order for the application of reagents in the Gram stain? A. B. C. D. E. Crystal violet, iodine, alcohol/acetone, safranin Iodine, safranin, crystal violet, alcohol/acetone Crystal violet, alcohol/acetone, iodine, safranin Crystal violet, safranin, iodine, alcohol/acetone Safranin, crystal violet, alcohol/acetone, iodine 56. The cell membrane, the cell wall, and the outer membrane comprise the ______. A. B. C. D. E. cell envelope slime layer glycocalyx S-layer peptidoglycan 57. During the Gram stain, the application of alcohol results in the decolorization of ______ cells. A. B. C. D. gram-positive gram-negative all pleomorphic 58. Mycobacterium and Nocardia are distinguished from other bacteria by the ______ stain. A. endospore B. basic C. methylene blue D. Gram E. acid-fast 59. The chemical bonds in peptidoglycan can be hydrolyed by the enzyme _____, found in tears and saliva. A. B. C. D. lysozyme penicillinase peptidase kinase 60. Lysozyme is most effective against ______. A. gram-positive organisms B. archaea C. mycoplasmas D. cyanobacteria E. gram-negative organisms True / False Questions 61. If the bacterial cells were viewed immediately after crystal violet was applied during the Gram stain procedure, gram-positive cells would be purple but gram-negative cells would be colorless. True False 62. The cell envelope of gram-positive bacteria has two layers: a thick cell wall and the cell membrane. True False 63. Hot carbol fuchsin is the primary dye in the acid-fast stain. True False 64. The region between the bacterial cell membrane and the cell wall is called the outer membrane. True False 65. Both gram-positive and gram-negative cells have outer membranes. True False Multiple Choice Questions 66. Chemotaxis refers to the ability of a cell to A. B. C. D. move in response to light. move in response to a chemical. transport desired molecules into a cell. halt movement in response to a chemical. 67. A nutrient binds to receptors near the flagellar basal body. This will result in A. B. C. D. inhibition of flagella rotation. numerous tumbles. clockwise rotation of flagella. counterclockwise rotation of flagella. 68. A bacterial cell exhibiting chemotaxis must have ______. A. B. C. D. E. a capsule flagella thylakoids metachromatic granules fimbriae True / False Questions 69. Flagella move in a whip-like motion. True False Multiple Choice Questions 70. Which external structure protects bacteria from phagocytosis? A. B. C. D. Cell membrane Capsule Fimbriae Slime layer 71. Two structures that allow bacteria to adhere to surfaces are ______ and ______. A. B. C. D. E. actin filaments; phospholipid membranes lipopolysaccharide; techoic acid endospores; metachromatic granules fimbriae; capsules pili; ribosomes 72. Spirochetes are able to move due to ______. A. B. C. D. E. cilia serving as walking feet a membrane-bound flagellum glycocalyx for gliding motility a periplasmic flagellum pseudopods 73. Two functions of bacterial appendages are ______ and ______. A. B. C. D. attachment; motility motility; energy production antibiotic resistance; motility attachment; energy production 74. The basal body of a flagellum is anchored into the ______. A. B. C. D. E. hook cell membrane cell wall peptidoglycan layer outer membrane 75. The term that refers to the presence of flagella all over the cell surface is ______. A. B. C. D. E. peritrichous lophotrichous monotrichous atrichous amphitrichous 76. The term that refers to the presence of a tuft of flagella emerging from a single site is ______. A. B. C. D. E. amphitrichous lophotrichous atrichous peritrichous monotrichous 77. The term that refers to flagella at both poles of the cell is ______. A. B. C. D. E. peritrichous atrichous monotrichous amphitrichous lophotrichous 78. The bacterial flagellum has three components. In order from the cytoplasm to the external environment, they are ______. A. B. C. D. E. hook, basal body, and filament filament, hook, and basal body filament, basal body, and hook basal body, hook, and filament basal body, filament, and hook 79. The short, numerous appendages used by some bacterial cells for adhering to surfaces are called ______. A. B. C. D. E. periplasmic flagella (axial filaments) flagella fimbriae cilia pili 80. The transfer of genes during bacterial conjugation involves rigid, tubular appendages called ______. A. B. C. D. E. periplasmic flagella (axial filaments) fimbriae sex pili cilia flagella True / False Questions 81. A slime layer gives bacterial cells greater pathogenicity than a capsule. True False Multiple Choice Questions 82. When bacilli in a chain fold back upon each other like a hinge, this cellular arrangement is termed a ______. A. B. C. D. E. strep staph sarcina tetrad palisade 83. An irregular cluster of spherical bacterial cells is termed ______. A. B. C. D. E. staphylospirillum streptobacillus staphylobacillus streptococcus staphylococcus 84. A chain of rod-shaped cells would be called a ______. A. B. C. D. E. palisade Staphylobacillus streptobacillus staphylococcus streptococcus 85. Which term is not used to describe bacterial cell shape? A. Spirochete B. Vibrio C. Coccus D. Bacillus E. Tetrad True / False Questions 86. The term diplococcus refers to an irregular cluster of spherical bacterial cells. True False Multiple Choice Questions 87. Bacterial cells could have any of the following appendages except ______. A. B. C. D. E. cilia fimbriae periplasmic flagella (axial filaments) flagella pili 88. Which of the following is not a characteristic of bacteria? A. B. C. D. Ribosomes are present as the site of protein synthesis. Organelles termed mitochondria are the site of ATP production. The cell wall is made of peptidoglycan or other distinct polysaccharides. DNA is free in the cytoplasm. True / False Questions 89. The bacterial cell membrane is a site for many enzymes and metabolic reactions. True False Multiple Choice Questions 90. Which of the following statements regarding chemotaxis is incorrect? A. In a cell with peritrichous flagella, each flagellum moves individually but in a coordinated direction during a run. B. In a tumble, the flagellum reverses direction, causing the cell to stop moving and change course. C. When a cell detects a nutrient gradient, it will increase the frequency of runs to move toward the nutrient. D. The fuel for flagellar motion is not ATP, but a proton gradient. 91. Alcohol-based hand sanitizers specifically target lipids, making them most effective when trying to eliminate ______. A. B. C. D. E. endospores biofilms gram-positives viruses gram-negatives 92. Which of the following properties are shared by both bacteria and archaea? A. B. C. D. Single, circular chromosome Method of DNA compaction Cell wall polysaccharides Ester linkages in fatty acids 93. The division of microbes termed the Mendosicutes have a cell wall type best described as ______. A. B. C. D. lacking a cell wall archaeal gram-positive gram-negative 94. The division of microbes termed the Firmicutes have a cell wall type best described as ______. A. B. C. D. gram-positive archaeal lacking a cell wall gram-negative