Kral, Microbiology Exam #3 (Pearson Questions)
8. The initial/first effect of ionizing radiation on a cell is that it causes
the formation of highly reactive ions.
9. Genetic change in bacteria can be brought about by
conjugation, transformation, transduction, and mutation.
All of the answers are correct.
10. Transformation is the transfer of DNA from a donor to a recipient cell
as naked DNA in solution.
11. Biotechnology involves the
use of microorganisms to make desired products, the use of animal cells to make vaccines, and the development of disease-resistant crop plants.
12. Which of the following is an advantage of using E. coli to make a human gene product?
Its genes are well known.
13. Restriction enzymes function as
bacterial enzymes that destroy phage DNA.
14. An agent used to reduce the number of bacteria on a toilet would most accurately be called a(n)
disinfectant.
15. Which of the following pairs of terms is mismatched?
bacteriostatic – kills vegetative bacterial cells
16. Which of the following regarding antimicrobial control agents is FALSE?
Most chemical agents can achieve sterility.
17. The most resistant of the bacterial endospores can withstand boiling for up to
20 hours.
18. If you were preparing nutrient agar at home and did not have an autoclave, what could you use to sterilize the nutrient agar?
Pressure cooker at 121°C for 15 minutes.
19. The preservation of beef jerky from microbial growth relies on which method of microbial control?
Desiccation.
20. All of the following are methods of food preservation EXCEPT
microwaves.
21. Which of the following could be used to sterilize plastic Petri plates in a plastic wrapper?
Gamma radiation.
22. Which of the following treatments is the most effective for controlling microbial growth? 140 Degrees C for 4 seconds
23. Which of the following methods is used to preserve food by slowing the metabolic processes of foodborne microbes?
Freezing.
24. Which of the following is a limitation of the autoclave?
It cannot be used with heat-labile materials.
25. Which of the following does NOT achieve sterilization?
Pasteurization.
26. Which of the following is the best method to sterilize heat-labile solutions?
Membrane filtration.
27. Ethylene oxide
is a sterilizing agent.
28. Which of the following results in lethal damage to nucleic acids?
Heat, radiation, and some chemicals.
29. Which concentration of ethanol is the most effective bactericide?
70 percent.
30. Which of the following is mismatched?
Florey and Chain – identification of Penicillium as the producer of penicillin.
31. More than half of our antibiotics are
produced by bacteria.
32. Most of the available antimicrobial agents are effective against
bacteria.
33. In the presence of penicillin, a cell dies because
it undergoes lysis.
34. Which of the following does NOT affect eukaryotic cells?
Semisynthetic penicillins.
35. Which of the following organisms would MOST likely be sensitive to natural penicillin?
Streptococcus pyogenes.
36. A drug that inhibits mitosis, such as griseofulvin, would be more effective against
fungi.
37. Drug resistance occurs
when antibiotics are used indiscriminately.
38. Which of the following statements about drug resistance is FALSE?
It is found only in gram-negative bacteria.
39. One effect of washing regularly with antibacterial agents is the removal of normal microbiota. This can result in
increased susceptibility to disease.
40. The major significance of Robert Koch's work is that
microorganisms cause disease.