Microbiology Exam 4

A cell that uses an inorganic carbon source and obtains its energy from light would be called

a. lithoautotroph

b. photoautotroph

c. chemoautotroph

d. autotroph

b. photoautotroph

Organisms that can grow at pH below 7 are called

a. neutrophiles

b. alkalinphiles

c. acidophiles

d. barophiles

c. acidophiles

Which of the following forms of oxygen is detoxified by the enzyme catalase?

a. a singlet oxygen

b. hydroxyl radical

c. peroxide anion

d. superoxide radical

c. peroxide anion

A colony of bacteria is an aggregation of cells:

a. arising from single parent cell

b. arising from a cfu

c. arising from the inoculum on the loop

d. at least 200 bacteria

e. both a and b

b. arising from a cfu

Which of the following organisms can cause disease in organisms whose body temperature is maintained at 37 degrees Celsius?

a. hyperthermophiles

b. mesophiles

c. thermophiles

d. psychrophiles

b. mesophiles

Barophiles will grow under:

a. high hydrostatic pressure

b. low pH

c. low nitrogen source

d. high carbon dioxide level

a. high hydrostatic pressure

A microbiologist inoculated a growth medium with 200 bacterial cells/ml. If the generation time of the species is 30 minutes, how many bacterial cells/ml will there be after 2 hrs of incubation?

a. 8,000

b. 4,000

c. 1,000

d. 3,2000

d. 3,2000

Which of the following is a best method for measuring the number of microbes when the large volume of sample with very low number of bacteria?

a. viable plate counts

b. turbidity

c. coulture counter

d. membrane filtration

d. membrane filtration

Obligate anaerobes lack one of the following enzymes that can protect them from the damaging effects of toxic oxygen.

a. ribozyme

b. superoxide dismutase

c. lipase

d. ligase

b. superoxide dismutase

A(n) ___ organism that is an aerobe but can grow and survive in anaerobic conditions.

a. obligate anaerobic

b. facultative anaerobic

c. obligate aerobic

d. both aerotolerant and anaerobic

b. facultative anaerobic

Microbes that will require 2-10% oxygen for their growth

a. acidophiles

b. barophiles

c. microaerophiles

d. alkalinophiles

c. microaerophiles

When one organism helps another to do better than alone, it is a ___.

a. symbiotic relationship

b. antagonistic relationship

c. biofilm

d. synergistic relationship

d. synergistic relationship

Biofilm is associated with___

a. chronic illness

b. uniport

c. a type of media to grow anaerobes

d. is a great movie

a. chronic illness

Hydrogen peroxide can be

a. detoxified by catalases

b. detoxified by carotenoids

c. broken down by biofilm

d. detoxified by superoxide dismutase

a. detoxified by catalases

Which of the following is a growth limiting factor for microbes?

a. nitrogen

b. heme

c. vitamins

d. water

a. nitrogen

Which of the following can grow at 4 degrees C?

a. hyperthermophiles

b. mesophiles

c. thermophiles

d. psychrophiles

d. psychrophiles

Which of the following is not part of the categories of microbe based on temperature requirement.

a. psychrophiles

b. mesophiles

c. thermophiles

d. microaerophiles

d. microaerophiles

Which of the following can grow on a nutrient agar plate on a laboratory bench?

a. an anaerobic bacterium

b. an aerobic bacterium

c. viruses on an agar surface

d. all the above

b. an aerobic bacterium

Which of the following statements is TRUE about broad-spectrum antimicrobial drugs?

a. they are effective against a few pathogens

b. they are effective against many pathogens

c. they do not allow superinfection to develop

d. they are effective against all pathogens

b. they are effective against many pathogens

Which of the following drugs kills bacteria by inhibition of protein synthesis?

a. penicillin

b. streptomycin

c. nucleotide analogs

d. tetracyline

e. both b and d

e. both b and d

Which of the following drugs kills bacteria by inhibition of DNA or RNA synthesis?

a. penicilin

b. cephalosporins

c. nucleotide analogs

d. tetracycline

c. nucleotide analogs

Penicillin is very effective for treating infections with Gram-positive bacteria but rarely causes side effects in humans. This is an example of

a. selective toxicity

b. superinfection

c. antibiotic resistance

d. altruism

a. selective toxicity

Which of the following drugs kills bacteria by inhibition of cell wall synthesis?

a. sulfonamides

b. cephalosporins

c. nucleotide analogs

d. tetracycline

b. cephalosporins

Which of the following drugs kills bacteria by inhibition of folic acid synthesis?

a. sulfonamides

b. cephalosporins

c. nucleotide analogs

d. tetracycline

a. sulfonamides

Original natural penicillin modified i the laboratory to make it more effective. This product would be a(n)

a. antibiotic

b. analog

c. semisynthetic antimicrobial

d. synthetic antimicrobial

c. semisynthetic antimicrobial

Which of the following drugs inhibit replication and transcription of DNA?

a. penicillin

b. quinolones

c. nucleotide analogs

d. tetracyline

b. quinolones

Which of the following drugs works on cytoplasmic membrane to kill bacteria?

a. polymyxin B

b. penicillin

c. sulfonamide

d. all the above

a. polymyxin B

Minimum inhibitory concentration (MIC) quantifies

a. the smallest amount of drugs that will inhibit a pathogen

b. the smallest amount of drug that will destroy all pathogen

c. the smallest amount of drug that will not be able to inhibit a pathogen

d. none of the above

a. the smallest amount of drugs that will inhibit a pathogen

Minimum bacteriocidal concentration (MBC) quantifies

a. the lowest concentration of drug that will kill a pathogen

b. the smallest amount of drug that will destroy all pathogen

c. the smallest amount of drug that will not be able to inhibit a pathogen

d. none of the above

a. the lowest concentration of drug that will kill a pathogen

Which of the following best describes cross resistance to antimicrobial drugs?

a. the deactivation of an antimicrobial agent by a bacterial enzyme

b. resistance to one antimicrobial agent confers resistance to similar drugs

c. resistance to three or more types of antimicrobial drug

d. resistance to new antimicrobial drug because of prolonged use of another drug

b. resistance to one antimicrobial agent confers resistance to similar drugs

What are/is the best criteria for selecting a drug for your patient?

a. selectively toxic against pathogen

b. easily administered

c. cheap even though it is not easy to administer

d. inexpensive even though it is not easy to administer

e. both a and b

e. both a and b

Which of the following is strictly narrow specturm?

a. tobramycin

b. penicillin

c. tetracyline

d. sulfonamides

a. tobramycin

What is the best method to select the most effective antibiotic for your patient?

a. viable plate method

b. turbidity test

c. membrane filtration

d. kirby-bauer test

d. kirby-bauer test

Which of the following can detect the zone of inhibition and MIC on the same plate?

a. E-test

b. Kirby Bauer test

c. Broth dilution test

d. all the above

a. E-test

Bacteriostatic refers to:

a. a drug that stops growth of bacteria

b. a drug that kills bacteria

c. a drug that helps bacteria grow faster

d. all the above

a. a drug that stops growth of bacteria

Which of the following can be a side effect of an antibiotic

a. disruption of normal microbiota

b. toxicity

c. allergy

d. all the above

d. all the above

In what way bacteria can acquire resistance to antibiotics?

a. by mutation in chromosomal genes

b. acquiring R-Plasmids from resistant bacteria

c. some are naturally resistance

d. all the above

d. all the above