Microbiology 2

Lecture Exam 1 (Practice)

Read each question carefully. If there is any doubt about the meaning of any question ask!! Good Luck!!

Multiple choice: Select the best answer.

1. Which of the following elements would be considered micronutrients a) sulphur b) oxygen c) carbon d) zinc e) phosphorus

2. The branch of microbiology dealing primarily with the body's defenses is a) protozoology b) biotechnology c) immunology d) epidemiology e) virology

3. Which of the following are not characteristics of bacterial slime layers of capsules a) they increase bacterial pathogenicity b) they help bacteria adhere to smooth surface c) they help bacteria escape phagocytosis d) they are essential for bacterial survival e) they help protect the cell from loss of water or nutrients

4. A microorganism which obtains carbon from carbon dioxide and energy from sunlight would be classified as a a) photoautotroph b) saprobe c) chemoautotroph d) photoheterotroph e) chemoheterotroph

5. Which of the following is not a characteristic of viruses a) they are obligate intracellular parasites b) they have a capsid made of protein c) they can contain either RNA or DNA d) they are classified in the Kingdom Monera e) they are not cells

6. Protein synthesis in bacteria is carried out using a) ribosomes b) chromatin c) inclusion bodies d) glycocalyx e) none of the above

7. The process of introducing a small sample of bacteria into a container of medium so that the sample will grow is called a) inoculation b) mixing c) selection d) incubation e) none of the above

8. A T-even bacteriophage would be most likely to infect a) a fungus b) a plant c) an animal d) a bacterium e) all are equally likely

9. Two organisms which are very different in most respects would be most likely to share the same a) order b) phylum c) class d) species e) family

10. Which of the following viral structures are formed from a part of the host cell's structure a) capsid b) nucleic acid c) capsomere d) envelope e) two of the above

11. A coccus which divides along a single plane would be most likely to produce what type of bacterial arrangement a) tetrad b) sarcina c) streptococci d) palisade e) diplobacilli

12. A culture in which only a single known species of microorganism is growing is known as a _________ culture a) pure b) mixed c) axenic d) known e) two of the above

13. You have just discovered a new virus. How many genes would you expect it to contain a) 0-2 b) 2-500 c) 500-5,000 d) 5,000-10,000 e) more than 10,000

14. Which of the following is a non-symbiotic association a) mutualism b) synergism c) parasitism d) commensalisms e) none of the above

15. All eukaryotic cells contain a) chloroplasts b) endoplasmic reticulum c) cell walls d) mitochondria e) two of the above

16. Which of the following correctly illustrates the proper order of size of an average cell, from smallest to largest of viruses, protozoans, bacilli, spirochetes a) virus, protozoa, bacillus, spirochete b) bacillus, virus, spirochete, protozoa c) virus, bacillus, protozoa, spirochete d) spirochete, protozoa, bacillus, virus e) none of the above

17. Bacteria found in extremely harsh environments (high salt, high temperature, extremes of pH etc.) would most likely be grouped with the a) gliding bacteria b) cyanobacteria c) mycoplasms d) rickettsias e) archaebacteria

18. A solution in which the solute concentration of the external environment is lower then the solute concentration of the cells internal environment would be described as being a) isotonic b) hypotonic c) hypertonic d) osmotonic e) none of the above

19. The proper use of binomial nomenclature to indicate the scientific name of an organism is a) Neisseria gonorrhoeae b) Neisseria Gonorrhoeae c) neisseeria gonorrhoeae d) Neisseria gonorrhoeae e) neisseria Gonorrhoeae

20. The motile, feeding stage of a protozoan's life cycle is known as a a) sporozoite b) cyst c) sarcodina d) ciliophora e) none of the above

21. Media can be classified according to a) chemical characteristics b) physical form c) functional type d) two of the above e) all of the above

22. According to the classification scheme outlined in Bergey's Manual, gram negative bacteria are members of the division a) Firmicutes b) Tenericutes c) Mendosicutes d) Gracilicutes e) Mollicutes

23. Viruses are classified by which of the following characteristics a) type of nucleic acid b) type of capsid c) presence of envelope d) two of the above e) none of the above

24. Cell walls help to protect bacterial cells from the effect of ---________ solutions a) hypertonic b) isotonic c) hypotonic d) all of the above e) none of the above

25. Characteristics of anabolic reactions include a) they synthesize cell structures b) they usually require the input of energy c) they usually break chemical bonds d) two of the above e) all of the above

26. The rough endoplasmic reticulum (RER) appears rough in electron micrographs because of a) high concentrations of phospholipids b) microtubutes within the RER c) multiple ribosomes on the surface of the RER d) the double membrane of the RER e) none of the above

27. Fungi are composed of many long, threadlike cells called _______. Masses of these long cells form ______. a) buds, hyphae b) mycelium, buds c) septa, buds d) mycelium, buds e) hyphae, mycelium

28. The study of an organism's structure would be part of the field of a) morphology b) physiology c) genetics d) phylogeny e) taxonomy

29. A mushroom would be classified in the phylum a) zygomycota b) ascomycota c) basidiomycota d) deuteromycota e) none of the above

30. A medium which contains salts, amino acids, copper sulfate, and milk would be classified as a) synthetic b) agar-based c) complex d) non-synthetic e) two of the above

31. A bacterium with small bundles of flagella emerging from one end of the cell would be described as ______ while a cell with flagella emerging from both ends would be described as being _______ a) amphitrichous, monotrichous b) peritrichous, lophotrichous c) lophotrichous, peritrichous d) lophotrichous, peritrichous e) lophotrichous, amphitrichous

32. Microorganisms detoxify harmful by-products of oxygen metabolism using the enzymes a) catalase b) polymerase c) superoxide dismutase d) two of the above e) all of the above

33. Those organisms with the longest evolutionary history (i.e. the oldest organisms) would be found in the Kingdom a) Myceteae b) Prokaryote c) Protista d) Plantae e) Animalia

34. Chronic latent infections are associated with viruses that cause a) herpes b) influenza c) chicken pox d) two of the above e) all of the above

35. A medium which inhibits bacterial growth while allowing the growth of fungi would be referred to as a) fungal b) selective c) differential c) reducing e) none of the above

36. Which of the following is not one of the properties which help to define cells as living entities a) growth b) self-assembly c) metabolism d) movement e) reproduction

37. Amino acids which must be obtained from a microbe's food (i.e. cannot be synthesized by the microorganism) are known as a) reduced b) exact c) strict d) fastidious e) essential

38. A fungus releasing an antibiotic into its environment in order to kill bacteria which would otherwise compete for nutrients would be an example of a) antagonism b) mutualism c) commensalism d) parasitism e) synergism

39. The fact that dogs (or humans for that matter) are never infected by feline leukemia virus is an example of a) viral lysogeny b) bacteriophage transit c) viral disparity d) viral host range e) none of the above

40. In a viable plate count, each ---- ______ represents a ______ from the sample population a) cell, colony b) colony, cell c) hour, generation d) cell, generation e) generation, cell

41. Microorganisms which obtain carbon in the form of organic matter from other organisms would be considered a) autotrophs b) lithotrophs c) heterotrophs d) chemotrophs e) auxotrophs

42. The ability of a microscope to show fine detail is a measure of that microscope's a) magnification b) refraction c) illumination d) resolution e) objectivity

43. Clear patches in cell culture which indicate sites of viral infection are called a) plaques b) colonies c) pocks d) spikes e) viroids

44. Differential staining techniques include which of the following a) Gram staining b) acid-fast staining c) negative staining d) two of the above e) all of the above

45. A microscope which transforms differences in density into differences in light intensity is a ---- _______ microscope a) bright field b) differential interference c) phase-contrast d) dark-field e) electron

46. A staining technique important in the identification of /Mycobacterium tuberculosis, Mycobacterium leprae /and /Nocardia /is a) Gram staining b) simple staining c) acid-fast staining d) endospore staining e) capsule staining

47. Bacteria found living only in places such as deep mud bogs, the bottom of a lake, or the large intestine would be classified as a) obligate aerobes b) facultative halophiles c) strict anaerobes d) two of the above e) all of the above

48. Which two components are found in all viruses a) an envelope and capsid b) an envelope and nucleic acid c) a capsid and nucleic acid d) an envelope and RNA e) RNA and DNA

49. Nitrogen is used by microorganisms primarily to synthesize a) DNA b) lipids c) membranes d) proteins e) two of the above

50. A type of bacterial transport system which requires the expenditure of bacterial energy is a) diffusion b) active transport c) facilitated diffusion d) pinocytosis e) two of the above

51. A refrigerator would be an ideal incubator for a a) thermophile b) facultative c) mesophile d) psychrophile e) osmophile

52. The most highly detailed views of cells are provided by the a) scanning electron microscope b) differential interference microscope c) phase contrast microscope d) fluorescent microscope e) transmission electron microscope

53. The time between two successive cell divisions is known as the a) generation time b) exponential time c) doubling time d) two of the above e) none of the above

Questions 54-58 deal with Gram positive and Gram negative cells. Mark A if the statement is most related to Gram positive cells, B for Gram negative cells, C for both cell types and D for neither cell type.

54. Overall thickness of the cell wall is greater than 20 nm.

55. Cell wall contains peptidoglycan.

56. Generally more difficult to inhibit or kill using antimicrobics.

57. Loss of cell wall results in formation of an L-form.

58. Loss of cell wall results in formation of a protoplast.

Questions 59-61 refer to eukaryotic cellular organelles. Mark A if the statement refers to the nucleus, B for the golgi apparatus, C for lysosomes, D for mitochondria, E for the cytoskeleton.

59. Composed of microtubules and microfilaments.

60. Responsible for conversion of light energy to chemical energy.

61. Involved in intracellular digestion of food particles.

True/False: Mark T for true, F for false.

62. Prokaryotic flagella whip back and forth to provide motility.

63. An advantage of the electron microscope is that it can produce color images.

64. Turbidity measurements of bacterial cultures cannot differentiate between live and dead cells.

65. Bacterial pili are found only on Gram (-) cells.

66. All algae are microscopic.

67. Some viruses contain single stranded DNA.

68. Oxygen is used by all microorganisms.

69. The higher a lens' numerical aperture, the better the resolution that lens will provide.

70. Nutrient agar and trypticase soy agar are considered general-purpose media.

71. Most microorganisms cause disease in humans and other organisms.

72. Bacteria and viruses are grouped in the same Kingdom.

73. Parasites obtain nutrients from the organic debris of decaying organisms.

74. Eukaryotic cells tend to be larger than prokaryotic cells.

75. Differential staining could be used to tell whether a cell is Gram positive or Gram negative.

Fill in: Supply the word that best completes the sentence/definition.

76. ________________ An organism which lives in habitats containing a high concentration of salt (greater than 25%).

77. ________________ Kingdom containing the (evolutionarily) oldest eukaryotic organisms.

78. ________________ A short, plump gently curved bacterium.

79. ________________ The phase of bacterial growth curve in which the rate of cell multiplication is the same as the rate of cell death.

80. ________________ The process of holding a container of media at a specific temperature to facilitate growth of the organisms in the media.

81. ________________ The sole carbon source of an autotrophy.

82. ________________ One word description of a culture containing only E. coli and S. marcesens.

83. ________________ A bacterial culture derived from a single parent that differs in structure or metabolism from other cultures of that species.

84. ________________ Portion of the viral multiplication cycle during which assembly of individual viral parts into whole active virions takes place.

85. ________________ The splitting of a parent bacterial cell to form a pair of similar sized molecules and produce energy.

86. ________________ Metabolic reactions which break down large molecules to small molecules and produce energy.

87. ________________ Organisms which require specific growth factors or complex nutrients are referred to as 87.

Short answer: Answer each question briefly but completely.

88. Name two genera which produce bacterial endospores and one disease caused by a spore forming bacterium. (3 points)

89. The eumycota (true fungi) are divided into four phyla. What characteristic is used to assign members to each of the four phyla? What are the names of each phyla? (3 points)

90. Relate the general structure of a typical enveloped virus using a simple drawing. Label all of the major parts of your drawing (there should be at least four). (3 points)

91. Differentiate between selective and differential media, give one example of one type, specifying whether it is differential or selective. (3 points)

92. What is the resolving power of a lens with a numerical aperture of 1.0 when using light with a wavelength of 500 nm. (3 points)

93. Given a bacterium with a generation time of 30 minutes and starting with ten viable cells in your culture, how many bacteria would you have in three hours? (3 points)

Answers

88. Bacillus, Clostridium; several diseases

89. Type of Sexual Spore produced; Zygomycota, Ascomycota, Basidiomycota, Deuteromycota

90. (Picture should be labeled with Spikes, Nucleic Acid, Capsid, and Envelope)

91. Selective- allows only a single type of microbe to grow (mannitol salt agar)

Differential- allows several species to grow but highlights differences between them (MacConkey)

92. RP= 500 nm/ 2 x 1 = 250 nm

93. N_F = (10)2⁶ = 640 cells