Microbiology Chapter 5

Psychrotroph A. this group requires oxygen for metabolism, just like us B. these organisms are present in compost piles and hot springs C. they do not or cannot use oxygen D. these organisms live at the bottom of the ocean E. they require relatively high levels of salt AB. they survive in environments where the concentration of oxygen is relatively low. AC. this group has most of the pathogens as they grow at body temperature AD. these have been found in seawater from hot water volcanic vents AE. they are insensitive to oxygen and still grow well when oxygen is present. BC. they grow in either the presence of or a reduced concentration of oxygen BD. they are able to withstand high pressure BE. they require an atmosphere low in oxygen but rich in carbon dioxide CD. they can tolerate acidic pH 2.0 to a pH 9.5

D

49. The agar in nutrient agar serves as a A. protein source. B. medium supplement. C. solidifying agent. D. All the above are correct.

C

Obligate aerobe A. this group requires oxygen for metabolism, just like us B. these organisms are present in compost piles and hot springs C. they do not or cannot use oxygen D. these organisms live at the bottom of the ocean E. they require relatively high levels of salt AB. they survive in environments where the concentration of oxygen is relatively low. AC. this group has most of the pathogens as they grow at body temperature AD. these have been found in seawater from hot water volcanic vents AE. they are insensitive to oxygen and still grow well when oxygen is present. BC. they grow in either the presence of or a reduced concentration of oxygen BD. they are able to withstand high pressure BE. they require an atmosphere low in oxygen but rich in carbon dioxide CD. they can tolerate acidic pH 2.0 to a pH 9.5

A

10. Which of the following is not one of the four phases of a bacterial growth curve? A. lead phase B. lag phase C. log phase D. stationary phase E. decline phase

A

2. How is asexual reproduction used in prokaryotic cells? A. an increase in the population size with each cell being identical to the parent cell B. mitosis is an orderly method of cloning the cell into two daughter cells C. meiosis is a process called reduction division D. budding is breaking off a piece of a cell off the surface of the parent cell

A

21. As a culture of Clostridium enters the decline phase of the growth curve, the vegetative cells will have A. produce endospores. B. synthesize a slime layer. C. lose their cell walls. D. form a thick capsule.

A

27. Endospores are found primarily in which kind of organisms? A. Gram positive bacillus B. Gram negative bacillus C. Gram positive coccus D. Gram negative coccus

A

38. A bacterium that grows only at the top of a thioglycollate broth tube should be classified as A. aerobic. B. facultative. C. anaerobic. D. microaerophilic.

A

41. An acidophile would grow best at a pH of A. 2. B. 6. C. 9. D. 12.

A

46. What are organisms called that require high amounts of salt? A. halophiles B. psychrotrophs C. facultative D. mesophiles

A

5. How does cytokinesis work in prokaryotes? A. an inward pinching of the cell envelope, tubulin homolog is part of the fission ring B. in gram positive cells, the cell envelope constricts, then the cells separate C. in gram negative cells a new septum forms between the daughter cells, then dissolves D. none of the above are correct

A

51. Which of the following types of media are examples of a chemically undefined medium, or complex medium? A. nutrient agar B. blood agar C. citrate agar D. all of the above are correct

A

52. A selective medium is one that A. allows one type of bacterium to grow while inhibiting another type. B. permits bacterial rods to grow while inhibiting cocci. C. contains nutrients on which only bacteria can grow. D. distinguishes colonies of one type of bacterium from those of another type.

A

7. Which of the following is not a limiting factor for the growth of microorganisms? A. not enough humidity B. not enough space C. too many waste products D. not enough nutrients

A

8. When relating generation time of microbes to disease, which is a correct general statement that could be made? A. The slower the generation time, the more symptoms a patient will develop. B. The faster the generation time, the shorter the incubation period. C. If the doubling time is very fast, then chances are the patient will get better faster. D. None of the above matter, it all depends on how many cells the patient becomes infected with.

B

Microaerophile A. this group requires oxygen for metabolism, just like us B. these organisms are present in compost piles and hot springs C. they do not or cannot use oxygen D. these organisms live at the bottom of the ocean E. they require relatively high levels of salt AB. they survive in environments where the concentration of oxygen is relatively low. AC. this group has most of the pathogens as they grow at body temperature AD. these have been found in seawater from hot water volcanic vents AE. they are insensitive to oxygen and still grow well when oxygen is present. BC. they grow in either the presence of or a reduced concentration of oxygen BD. they are able to withstand high pressure BE. they require an atmosphere low in oxygen but rich in carbon dioxide CD. they can tolerate acidic pH 2.0 to a pH 9.5

AB

Mesophile A. this group requires oxygen for metabolism, just like us B. these organisms are present in compost piles and hot springs C. they do not or cannot use oxygen D. these organisms live at the bottom of the ocean E. they require relatively high levels of salt AB. they survive in environments where the concentration of oxygen is relatively low. AC. this group has most of the pathogens as they grow at body temperature AD. these have been found in seawater from hot water volcanic vents AE. they are insensitive to oxygen and still grow well when oxygen is present. BC. they grow in either the presence of or a reduced concentration of oxygen BD. they are able to withstand high pressure BE. they require an atmosphere low in oxygen but rich in carbon dioxide CD. they can tolerate acidic pH 2.0 to a pH 9.5

AC

Hyperthermophile A. this group requires oxygen for metabolism, just like us B. these organisms are present in compost piles and hot springs C. they do not or cannot use oxygen D. these organisms live at the bottom of the ocean E. they require relatively high levels of salt AB. they survive in environments where the concentration of oxygen is relatively low. AC. this group has most of the pathogens as they grow at body temperature AD. these have been found in seawater from hot water volcanic vents AE. they are insensitive to oxygen and still grow well when oxygen is present. BC. they grow in either the presence of or a reduced concentration of oxygen BD. they are able to withstand high pressure BE. they require an atmosphere low in oxygen but rich in carbon dioxide CD. they can tolerate acidic pH 2.0 to a pH 9.5

AD

Aerololerant A. this group requires oxygen for metabolism, just like us B. these organisms are present in compost piles and hot springs C. they do not or cannot use oxygen D. these organisms live at the bottom of the ocean E. they require relatively high levels of salt AB. they survive in environments where the concentration of oxygen is relatively low. AC. this group has most of the pathogens as they grow at body temperature AD. these have been found in seawater from hot water volcanic vents AE. they are insensitive to oxygen and still grow well when oxygen is present. BC. they grow in either the presence of or a reduced concentration of oxygen BD. they are able to withstand high pressure BE. they require an atmosphere low in oxygen but rich in carbon dioxide CD. they can tolerate acidic pH 2.0 to a pH 9.5

AE

11. At what stage in the bacterial growth curve are there no cell divisions occurring, because the bacteria are adapting to their new environment? A. lead phase B. lag phase C. log phase D. stationary phase E. decline phase

B

12. At what stage of a bacterial growth curve are the bacteria growing in size, storing nutrients, and synthesizing enzymes in preparation for binary fission? A. lead phase B. lag phase C. log phase D. stationary phase E. decline phase

B

23. Endospores are heat-stable resting forms of all of the bacteria listed below, except A. Bacillus anthracis. B. Escherichia coli. C. Clostridium perfringens. D. Clostridium botulinum

B

25. Under what conditions would you find vegetative growth from Clostridium botulinum endospores? A. high amounts of oxygen B. a vacuumed sealed can of food C. on the surface of machinery like in the mail sorting room D. on the surface of the skin

B

29. Which of the following conditions are most likely to affect the growth of bacteria? A. acidity, the amount of water present and calcium B. temperature, oxygen and pH C. osmosis, heat and salt D. temperature, pressure and salinity

B

30. An organism that grows at 5° C is classified as a A. mesophile. B. psychrophile. C. thermophile. D. facultative organism.

B

34. An example of a mesophile that is the most frequently identified cause of infective diarrhea is A. Staphylococcus aureus B. Campylobacter C. Clostridium D. Bacillus

B

39. A bacterium that grows turbid throughout a thioglycollate broth tube should be classified as A. aerobic. B. facultative. C. anaerobic. D. microaerophilic.

B

4. Archaea reproduce by a process known as A. meiosis. B. binary fission. C. mitosis. D. spontaneous generation.

B

43. Most bacteria grow best at A. acid pH B. neutral pH C. basic pH D. none of the above

B

45. The stomach protects us from a large number of microbes that might be in our food because A. of the amount of time food spends in the stomach. B. of it's high level of acidity. C. of the number of enzymes that digest food and bacteria. D. of the constant churning of the stomach.

B

48. Some organisms like Neisseria grow well in an atmosphere that is low in oxygen and rich in carbon dioxide. This can be created by lighting a candle, putting it in a jar, inserting the culture medium, then closing the lid of the jar. What is the best name for these organisms? A. aerobes B. capnophiles C. microaerophiles D. anaerobes

B

Thermophile A. this group requires oxygen for metabolism, just like us B. these organisms are present in compost piles and hot springs C. they do not or cannot use oxygen D. these organisms live at the bottom of the ocean E. they require relatively high levels of salt AB. they survive in environments where the concentration of oxygen is relatively low. AC. this group has most of the pathogens as they grow at body temperature AD. these have been found in seawater from hot water volcanic vents AE. they are insensitive to oxygen and still grow well when oxygen is present. BC. they grow in either the presence of or a reduced concentration of oxygen BD. they are able to withstand high pressure BE. they require an atmosphere low in oxygen but rich in carbon dioxide CD. they can tolerate acidic pH 2.0 to a pH 9.5

B

37. A bacterium that grows only at the bottom of a thioglycollate broth tube should be classified as A. aerobic. B. facultative. C. anaerobic. D. microaerophilic.

C

Facultative anaerobe A. this group requires oxygen for metabolism, just like us B. these organisms are present in compost piles and hot springs C. they do not or cannot use oxygen D. these organisms live at the bottom of the ocean E. they require relatively high levels of salt AB. they survive in environments where the concentration of oxygen is relatively low. AC. this group has most of the pathogens as they grow at body temperature AD. these have been found in seawater from hot water volcanic vents AE. they are insensitive to oxygen and still grow well when oxygen is present. BC. they grow in either the presence of or a reduced concentration of oxygen BD. they are able to withstand high pressure BE. they require an atmosphere low in oxygen but rich in carbon dioxide CD. they can tolerate acidic pH 2.0 to a pH 9.5

BC

42. How does the GasPak system work? A. The GasPak works like a vacuum, sucking the oxygen out of the container. B. The GasPak releases excess carbon dioxide, which replaces the oxygen. C. The hydrogen in the GasPak reacts with oxygen in the presence of a catalyst to form water, thereby creating an oxygen-free atmosphere. D. None of the above are true.

C

47. There are some mesophilic bacteria that are salt tolerant. An example is A. Escherichia B. Salmonella C. Staphylococcus D. Neisseria

C

Barophile A. this group requires oxygen for metabolism, just like us B. these organisms are present in compost piles and hot springs C. they do not or cannot use oxygen D. these organisms live at the bottom of the ocean E. they require relatively high levels of salt AB. they survive in environments where the concentration of oxygen is relatively low. AC. this group has most of the pathogens as they grow at body temperature AD. these have been found in seawater from hot water volcanic vents AE. they are insensitive to oxygen and still grow well when oxygen is present. BC. they grow in either the presence of or a reduced concentration of oxygen BD. they are able to withstand high pressure BE. they require an atmosphere low in oxygen but rich in carbon dioxide CD. they can tolerate acidic pH 2.0 to a pH 9.5

BD

Capnophile A. this group requires oxygen for metabolism, just like us B. these organisms are present in compost piles and hot springs C. they do not or cannot use oxygen D. these organisms live at the bottom of the ocean E. they require relatively high levels of salt AB. they survive in environments where the concentration of oxygen is relatively low. AC. this group has most of the pathogens as they grow at body temperature AD. these have been found in seawater from hot water volcanic vents AE. they are insensitive to oxygen and still grow well when oxygen is present. BC. they grow in either the presence of or a reduced concentration of oxygen BD. they are able to withstand high pressure BE. they require an atmosphere low in oxygen but rich in carbon dioxide CD. they can tolerate acidic pH 2.0 to a pH 9.5

BE

13. At what stage of a bacterial growth curve are the bacteria dividing rapidly and the graph is rising in a straight line? A. lead phase B. lag phase C. log phase D. stationary phase E. decline phase

C

14. In humans at what stage of the bacterial growth curve are disease symptoms developing because the bacteria are causing tissue damage? A. lead phase B. lag phase C. log phase D. stationary phase E. decline phase

C

15. At what point in the bacterial growth curve are bacteria the most vulnerable to antibiotics? A. lead phase B. lag phase C. log phase D. stationary phase E. decline phase

C

16. At what phase does broth become turbid and visible colonies appear on agar in the bacterial growth curve? A. lead phase B. lag phase C. log phase D. stationary phase E. decline phase

C

24. Endospores are very difficult to destroy. Because of this, which of the following techniques will work to get rid of them? A. dehydration or dessication B. boil at 100o C for an hour C. heat them under high pressure for several hours D. place in 70 % ethyl alcohol over night

C

3. The interval of time between successive binary fissions of a cell or population of cells is known as the A. separation time. B. growth phase. C. generation time. D. incubation period.

C

33. Most of the human pathogens are A. psychrophiles B. thermophiles C. mesophiles D. hyperthermophiles

C

36. Facultative bacteria are those that A. grow on natural and synthetic media. B. produce spores or capsules, but not both. C. grow in the presence or absence of oxygen. D. possess cell membranes but no cell walls.

C

53. A soil sample is added to a culture medium that has been designed to promote the growth of the genus Pseudomonas while inhibiting the growth of fungi. This test uses a(n) A. differential medium. B. natural medium. C. selective medium. D. minimal medium.

C

9. In the log phase of growth A. the death rate is equivalent to the reproductive rate. B. spore formation is a common event. C. the number of cells in the population increases rapidly. D. the growth curve is at a plateau.

C

Anaerobe A. this group requires oxygen for metabolism, just like us B. these organisms are present in compost piles and hot springs C. they do not or cannot use oxygen D. these organisms live at the bottom of the ocean E. they require relatively high levels of salt AB. they survive in environments where the concentration of oxygen is relatively low. AC. this group has most of the pathogens as they grow at body temperature AD. these have been found in seawater from hot water volcanic vents AE. they are insensitive to oxygen and still grow well when oxygen is present. BC. they grow in either the presence of or a reduced concentration of oxygen BD. they are able to withstand high pressure BE. they require an atmosphere low in oxygen but rich in carbon dioxide CD. they can tolerate acidic pH 2.0 to a pH 9.5

C

Acidophile A. this group requires oxygen for metabolism, just like us B. these organisms are present in compost piles and hot springs C. they do not or cannot use oxygen D. these organisms live at the bottom of the ocean E. they require relatively high levels of salt AB. they survive in environments where the concentration of oxygen is relatively low. AC. this group has most of the pathogens as they grow at body temperature AD. these have been found in seawater from hot water volcanic vents AE. they are insensitive to oxygen and still grow well when oxygen is present. BC. they grow in either the presence of or a reduced concentration of oxygen BD. they are able to withstand high pressure BE. they require an atmosphere low in oxygen but rich in carbon dioxide CD. they can tolerate acidic pH 2.0 to a pH 9.5

CD

1. The process by which bacteria reproduce is known as A. meiosis. B. splitting. C. mitosis. D. binary fission.

D

17. At what stage of the bacterial growth curve do the reproductive and death rates equalize? A. lead phase B. lag phase C. log phase D. stationary phase E. decline phase

D

18. At what phase in the bacterial growth curve in a patient do antibodies from the immune system and phagocytosis by white blood cells affect the progress of the disease? A. lead phase B. lag phase C. log phase D. stationary phase E. decline phase

D

19. In a culture tube at what phase of the bacterial growth curve do available nutrients become scarce and waste products begin to accumulate? A. lead phase B. lag phase C. log phase D. stationary phase E. decline phase

D

22. Which one of the following diseases does not involve endospores? A. Anthrax B. Botulism C. Tetanus D. Syphilis

D

26. Under the conditions of bioterrorism where were endospores from Bacillus anthracis found? A. inside an envelope B. on the surface of the skin C. on the surface of machinery like in the mail sorting room D. all of the above are correct

D

28. Which of the following diseases are all caused by endospore forming Clostridia? A. botulism B. gas gangrene C. tetanus D. all of the above are correct

D

31. Psychrophiles and thermophiles differ with respect to their A. oxygen requirements. B. ability to tolerate salt. C. pH requirements. D. best temperature for growth.

D

32. A mesophilic bacterium could A. reproduce at 37° C B. produce human disease. C. grow at human body temperature. D. All the above are correct.

D

35. Bacteria that can grow only in the absence of oxygen are said to be A. aerobic. B. microaerophilic. C. facultative. D. anaerobic.

D

40. You have isolated an organism from the human intestinal tract. It grows better when you capped the culture tube with a semiporous plug than when you used a plug that is completely permeable to oxygen. This organism should be classified as a(n) A. aerobe. B. anaerobe. C. facultative organism. D. microaerophile.

D

44. ______________ are important food producing bacteria because they can be used to produce dairy products like buttermilk, sour cream and yogurt from milk and cream. A. Aerobes B. Facultative anerobes C. Alkalinophiles D. Acidophiles

D

50. An important contribution was made to microbiology with the introduction of agar by Robert Koch. Which of the following statements about agar is correct? A. it contains no essential nutrients B. it remains liquid until cooled below 36oC C. as a solid in a petri dish it is useful to isolate pure colonies D. All of the above are correct.

D

54. How can you take a mixed unknown sample and separate out pure colonies to identify them? A. the pour plate method of mixing the sample with melted agar, then poured into petri dishes and allowed to harden B. a sterile loop can take a sample and streak for isolation onto an agar plate C. an individual colony can be subcultured onto another agar plate D. all of the above are possible

D

55. Which of the following methods of measuring population growth is a direct count? A. a turbidity count B. using a spectrophotometer to determine an increase of cells C. getting an optical density reading which is a function of the number of cells present D. standard plate count using a dilution series

D

6. Which of the following statements about generation time is correct? A. Under optimal conditions some prokaryotes have a very fast generation time of 20-30 minutes. B. Some organisms have much slower generation times of 20-30 hours. C. Most organisms have about the same generation time of about 24 hours. D. Both A and B, but not C are correct. E. A, B and C are correct.

D

20. In a bacterial growth curve, when the number of dying cells exceeds the number of new cells formed, what stage are they in? A. lead phase B. lag phase C. log phase D. stationary phase E. decline phase

E

Halophile A. this group requires oxygen for metabolism, just like us B. these organisms are present in compost piles and hot springs C. they do not or cannot use oxygen D. these organisms live at the bottom of the ocean E. they require relatively high levels of salt AB. they survive in environments where the concentration of oxygen is relatively low. AC. this group has most of the pathogens as they grow at body temperature AD. these have been found in seawater from hot water volcanic vents AE. they are insensitive to oxygen and still grow well when oxygen is present. BC. they grow in either the presence of or a reduced concentration of oxygen BD. they are able to withstand high pressure BE. they require an atmosphere low in oxygen but rich in carbon dioxide CD. they can tolerate acidic pH 2.0 to a pH 9.5

E