Quincy College

BIO 151

Exam 3

1)Antibiotics that affect various strains of Gram-positive bacteria and various strains of Gram- negative bacteria are called

1. 1. isolated usable.
   2. stress-induced.
   3. broad-spectrum.
   4. narrow-spectrum.

2. Which one of the following does NOT belong with the others?
   1. streptomycin
   2. cephalosporin
   3. ampicillin
   4. penicillin
   5. vancomycin

3. Which of the following bacteria have an innate resistance to penicillin?
   1. Mycoplasma
   2. Staphylococcus aureus
   3. Staphylococcus epidermis
   4. Micrococcus luteus

4. To date, most of our natural antibiotics have been found to be produced by members of what genus?
   1. Streptomyces
   2. Bacillus
   3. Penicillium
   4. Paenibacillus
   5. Cephalosporium

5. Which of the following antibiotics is recommended for use against gram-negative bacteria?
   1. polyenes
   2. cephalosporin
   3. penicillin
   4. polymyxin

6. Which of the following antibiotics does NOT interfere with cell wall synthesis?
   1. cephalosporins

1. 2. erythromycin
   3. penicillins
   4. ampicillin
   5. vancomycin

7. Which of the following organisms would MOST likely be sensitive to natural penicillin?
   1. E. coli
   2. Streptococcus pyogenes
   3. penicillinase-producing Neisseria gonorrhoeae
   4. Penicillium
   5. Mycoplasma

8. Which of the following does NOT affect eukaryotic cells?
   1. antiprotozoan drugs
   2. antihelminthic drugs
   3. antifungal drugs
   4. nucleotide analogs
   5. semisynthetic penicillins

9. Use of antibiotics in animal feed leads to antibiotic-resistant bacteria because
   1. bacteria from other animals replace those killed by the antibiotics.
   2. the few surviving bacteria that are affected by the antibiotics develop immunity to the antibiotics, which they pass on to their progeny.
   3. the antibiotics cause new mutations to occur in the surviving bacteria, which results in resistance to antibiotics.
   4. the antibiotics kill susceptible bacteria, but the few that are naturally resistant live and reproduce, and their progeny repopulate the host animal.
   5. the antibiotics persist in soil and water.

10. A drug that inhibits microtubule formation and kills helmiths, would be lest effective against

1. protozoans.
2. fungi.
3. bacteria.
4. mycobacteria.

11. Which of the following antibiotics are used to treat fungal infections?

1. aminoglycosides                2.            cephalosporins

3. griseofulvin                          4.            polyenes                             5.            bacitracin

1. 1, 2, and 3
2. 3 and 4
3. 3, 4, and 5

4. 4 and 5
5. All of these antibiotics are used to treat fungal infections.

12. Lamisil is an allylamine used to treat dermatomycoses. Lamisil's method of action is similar to that of

1. polymyxin B.
2. azole antibiotics.
3. echinocandins.
4. griseofulvin.
5. bacitracin.

13. Niclosamide prevents ATP generation in mitochondria. You would expect this drug to be effective against

1. gram-negative bacteria.
2. gram-positive bacteria.
3. helminths.
4. Mycobacterium tuberculosis.
5. viruses.

14. A drug that inhibits mitosis, such as griseofulvin, would be more effective against

1. gram-positive bacteria.
2. gram-negative bacteria.
3. fungi.
4. wall-less bacteria.
5. mycobacteria.

15. DNA transfer by conjugation is more efficient in a liquid medium setting, subjected to very mild agitation (stirring), rather than on an agar plate format. Why?

1. Direct cell-to-cell contact is required for this process, and this is more likely to be achieved in the plate format than in the fluid format (especially for relatively non-motile types of bacteria).
2. Direct cell-to-cell contact isn't required for this process, so the ability to secrete the DNA into the surrounding fluid medium makes the process more efficient than the dry surface of an agar plate.
3. Direct cell-to-cell contact is required for this process, and this is more likely to be achieved in the fluid liquid format than on an agar plate (especially for relatively non-motile types of bacteria).
4. Trick question-it can take place with the same degree of efficiency on either format. It doesn't matter!

16. The arsenic compound that was the first antimicrobial drug and proved highly effective in treating syphilis was called

1. penicillin.
2. sulfa.
3. erythromycin.
4. salvarsan.

17. The lowest concentration of a drug that prevents growth of a microorganism is the

1. infectious dose.
2. lethal dose
3. effective dose
4. minimum inhibitory concentration

18. Which of the following drugs does NOT block cell wall synthesis?
    1. Rifamycin.
    2. Bacitracin.
    3. Penicillin.
    4. Cephalosporin.

19. The lowest concentration of a drug that prevents growth of a microorganism is the

1. infectious dose.
2. lethal dose
3. effective dose
4. minimum inhibitory concentration

20. When a pathogen produces beta-lactamase, which antibiotics could be most effective?

1. Penicillin V.
2. Ampicillin.
3. Amoxicillin.
4. Vancomycin.

21. The target of most antifungal drugs is

1. nucleus.
2. ribosomes.
3. ergosterol.
4. cell cycle.

22. Which of the following should be used to treat a patient with viral infection?

1. acyclovir.
2. echinocandin.