70 terms

Chapter 3 Laboratory

1. The Six I's of studying microorganisms include all of the following except
2. All of the following are examples of different types of microbiological media except
petri dish.
3. The term that refers to the purposeful addition of microorganisms into a laboratory nutrient medium is
4. Which of the following is essential for development of discrete, isolated colonies?
solid medium
5. A pure culture contains only
one species of microorganism.
6. Which of the following will result when 1% to 5% agar is added to nutrient broth, boiled and cooled?
a solid medium
7. A microbiologist inoculates Staphylococcus aureus into a culture medium. Following incubation, both Staphylococcus aureus and Staphylococcus epidermidis are determined to be growing in this culture. What is the most likely explanation?
The culture is contaminated.
8. A microbiologist inoculates Staphylococcus epidermidis and Escherichia coli into a culture medium. Following incubation, only the E. coli grows in the culture. What is the most likely explanation?
The culture medium must be selective.
9. Which method often results in colonies developing down throughout the agar and some colonies on the surface?
pour plate
10. A common medium used for growing fastidious bacteria is
blood agar.
11. A nutrient medium that has all of its chemical components identified and their precise concentrations known and reproducible would be termed
12. A reducing medium contains
substances that remove oxygen.
13. Which type of medium is able to distinguish different species or types of microorganisms based on an observable change in the colonies or in the medium?
14. A microbiologist decides to use a nutrient medium that contains thioglycolic acid. What type of microbe is she attempting to culture?
15. For which bacterial genus is mannitol salt agar selective?
16. A microbiologist must culture a patient's feces for intestinal pathogens. Which of the following would likely be present in selective media for analyzing this fecal specimen?
bile salts
17. Which of the following characteristics refers to the microscope's ability to show two separate entities as separate and distinct?
resolving power
18. Which of the following magnifies the specimen to produce the real image of the specimen?
objective lens
19. If a microbiologist is studying a specimen at a total magnification of 950X, what is the magnifying power of the objective lens if the ocular lens is 10X?
20. All of the following are diameters of cells that would be resolved in a microscope with a limit of resolution of 0.2 µm except
0.1 µm.
The wavelength of light used plus the numerical aperture governs
22. The type of microscope in which you would see brightly illuminated specimens against a black background is
23. This microscope does not use light in forming the specimen image:
24. This microscope achieves the greatest resolution and highest magnification:
25. This microscope shows cells against a bright background and also shows intracellular structures of unstained cells based on their varying densities:
26. This microscope is the most widely used and shows cells against a bright background:
27. All of the following pertain to the fluorescence microscope except it
uses electron's to produce a specimen image.
28. Which is incorrect about chocolate agar?
It has chocolate extract in it.
29. Which microscope bombards a whole, metal-coated specimen with electrons moving back and forth over it?
scanning electron
30. The specimen preparation that is best for viewing cell motility is
hanging drop.
31. The primary purpose of staining cells on a microscope slide is to
add contrast in order to see them better.
32. The Gram stain, acid-fast stain, and endospore stain have the following in common:
are differential stains
33. Basic dyes are
attracted to the acidic substances of bacterial cells.
34. A microbiologist makes a fixed smear of bacterial cells and stains them with Loeffler's methylene blue. All the cells appear blue under the oil lens. This is an example of
simple staining.
35. Media that contains extracts from plants, animals, or yeasts are
36. Brain-heart infusion, trypticase soy agar (TSA), and nutrient agar are all examples of which type of media?
37. Bacteria that require special growth factors and complex organic substances are called
38. A media is designed that allows only staphylococci to grow. In addition, S. aureus colonies have a yellow halo around them and other staphylococci appear white. This type of media is
both selective and differential.
39. All of the following are examples of basic dyes except
40. Which type of media can be used to determine if a bacteria is motile?
41. All of the following are correct about agar except
it is a source of nutrition for bacteria.
42. Which of the following media is useful for cultivating fungi?
Sabouraud's agar
43. Which of the following puts the Six "I"s in their correct order?
inoculation, incubation, isolation, inspection, identification
44. Why is oil of immersion often used when viewing specimens under the microscope?
to increase the resolution
45. The procedure for culturing a microorganism requires the use of a microscope. True False
46. One colony typically develops from the growth of several parent bacterial cells. True False
47. Some microbes are not capable of growing on artificial media. True False
48. Mixed cultures are also referred to as contaminated cultures. True False
49. A medium that is gel-like has less agar in it compared to a solid medium. True False
50. A selective medium contains one or more substances that inhibit growth of certain microbes in order to facilitate the growth of other microbes. True False
51. A bacterial species that grows on blood agar but will not grow on trypticase soy agar is termed an anaerobe. True False
52. Fixed smears of specimens are required in order to perform the Gram stain and endospore stain on the specimens. True False
53. The bending of light rays as they pass from one medium to another is called refraction. True False
54. At the end of the Gram stain, gram-positive bacteria will be seen as purple cells. True False
55. Scanning tunneling and atomic force microscopes are used to image the detailed structure of biological molecules. True False
56. The correct microbiological term for the tiny sample of specimen that is put into a nutrient medium in order to produce a culture is the _____.
The three physical forms of laboratory media are: solid, semisolid, and___
58. Bacteria that require special growth factors and complex nutrients are termed _____.
59. _____ is the term for a culture made from one isolated colony.
pure culture
60. Newly inoculated cultures must be _____ at a specific temperature and time to encourage growth.
61. Magnification is achieved in a compound microscope through the initial magnification of the specimen by the _____ lens. This image is then projected to the _____ lens that will further magnify the specimen to form a virtual image received by the eye.
objective, ocular
62. The _____ of the microscope holds and allows selection of the objective lenses.
63. _____ dyes have a negative charge on the chromophore and are repelled by bacterial cells.
64. _____ has the same optical qualities as glass and thus prevents refractive loss of light as it passes from the slide to the objective lens.
Immursion oil
65. Which of the following reagents reacts with crystal violet as the mordant?
Gram's iodine
66. How will E. coli appear if the mordant is not applied?
67. Observing and characterizing colonial growth for size, shape, edge, elevation, color, odor, and texture is part of ___.
68. In lab, Tom was given a mixed culture. His objective is to isolate single colonies. What should be used to accomplish this goal?
Inoculating loop, incinerator, streak plate method, 37 degree Celsius incubator
69. Sally had a throat sample taken at a satellite lab within her health care provider's office. What kind of media would be best suited for this specimen?
Transport media
70. Identification relies entirely on biochemical test results. True False