Micro Test 3 Questions 26 to 49
28. Most bacteria reproduce by A. Binary fission B. Fragmentation C. Mitosis D. Budding E. Aerial Hyphae
A. Binary fission
30. Most fungi grow best at a pH of A. 1 B. 5 C. 7 D. 9 E. 14
B. 5
44. Which of the following substances is used for surgical hand scrubs? A. Chlorine belach B. Chlorhexidine C. Soap D. Glutaraldehyde C. Phenol
B. Chlorhexidine
27. The term aerotolerant anaerobe refers to an organism that A. Uses oxygen or grows without oxygen B. Does not use oxygen but tolerates it C. Requires less oxygen than is present in air D.. Requires more oxygen than is present in air E. Is killed by oxygen
B. Does not use oxygen but tolerates it
26. Salts and Sugars work to preserve food by creating a A. Hypotonic environment B. Hypertonic environment C. Lower osmotic pressure D. Depletion of nutrients
B. Hypertonic environment
43. Which of the following best describes the pattern of microbial death? A. All the cells in a culture die at once B. The cells in a population die at a constant rate C. Not all the cells in a culture are killed D. The pattern varies depending on the species E. The pattern cares depending on the antimicrobial agent.
B. The cells in a population die at a constant rate
29. Most bacteria grow best at a pH of A. 1 B. 5 C. 7 D. 9 E. 14
C. 7
32. An experiment began with 4 cells and ended with 128 cells. How many generations did the cells go through? A. 64 B. 32 C. 6 D. 5 E. 4
D. 5
31. Which of the following is the best definition of generation time? A. The length of time needed for lag phase B. The duration of log phase C. The minimum rate of doubling D. The length of time needed for a cell to divide E. The time needed for nuclear division
D. The length of time needed for a cell to divide
45. An agent used to reduce the number of bacteria on a toilet would be most accurately be called a(n) A. Antiseptic B. Aseptic C. Fungicide D. Virucide E. Disinfectant
E. Disinfectant
35. T/F. Pure cultures can easily be obtained on streak plates, even if the desired bacteria are present in very low concentrations.
False
38. T/F. Most pathogenic bacteria are thermophiles.
False
47. T/F. The pH of the medium has no effect on the activity of the disinfectant being applied.
False
48. T/F. Ultraviolet light causes irreversible breaks in DNA strands.
False
33. T/F. Bacterial Growth refers to an increase in the numbers of cells in a bacterial culture.
True
34.T/F. Bacterial Growth refers to an increase in the numbers of cells in a bacterial culture.
True
36. T/F. Agar is used as a solidifying agent in microbiological media since few bacteria can degrade it.
True
37. T/F. Laboratory coltivazione of obligate anaerobes requires reducing media or special growth chambers filled with inert gas.
True
39. T/F. Turbidity is an indirect measurement of bacterial growth that can be measured using spectrophotometer.
True
40. T/F. Filtration methods are used to count bacteria present in very low concentrations, such as in lakes and streams.
True
41. T/F. Filtration methods are used to count bacteria present in very low concentrations, such as in lakes and streams.
True
42. Nitrogen-fixing bacteria, such as cyanobacteria, can use atmospheric nitrogen (N2) for their nitrogen source.
True
46. T/F. Pseudomonas has been found growing in quaternary ammonium compounds (quats).
True
49. T/F. Autoclaving is the most effective method of moist heat sterilization.
True
