Mirco

Front 1

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

Select one:

a. Gram-positive bacteria.

b. Mycobacteria.

c. Fungi.

d. Wall-less bacteria.

e. Gram-negative bacteria.

Back 1

c. Fungi.

Front 2

Antimicrobial peptides work by

Select one:

a. Complementary base pairing with DNA.

b. Disrupting the plasma membrane.

c. Inhibiting cell-wall synthesis.

d. Hydrolyzing peptidoglycan.

e. Inhibiting protein synthesis.

Back 2

Disrupting the plasma membrane.

Front 3

Drug resistance occurs

Select one:

a. When antibiotics are used indiscriminately.

b. Because bacteria are normal microbiota.

c. Against antibiotics and not against synthetic chemotherapeutic agents.

d. When antibiotics are taken after the symptoms disappear.

e. All of the above.

Back 3

a. When antibiotics are used indiscriminately.

Correct

Front 4

The antibiotic tetracycline binds to the 30S subunit of the ribosome as shown in Figure 20.1. The effect is to

Select one:

a. Prevent attachment of tRNA.

b. Prevent transcription.

c. Stop the ribosome from moving along the mRNA.

d. Prevent attachment of tRNA and mRNA.

e. Prevent peptide bond formation.

Back 4

e. Prevent peptide bond formation.

Front 5

The antibiotic cycloheximide binds to the 60S subunit of the ribosome as shown in Figure 20.2. The effect is to

Select one:

a. Prevent transcription in prokaryotes.

b. Prevent polypeptide elongation in eukaryotes.

c. Prevent ribosome formation in bacteria.

d. Prevent peptide bond formation in prokaryotes.

e. Prevent mRNAribosome binding in eukaryotes.

Back 5

b. Prevent polypeptide elongation in eukaryotes.

Front 6

The antibiotic streptomycin binds to the 30S subunit of the ribosome as shown in Figure 20.4. The effect is to

Select one:

a. Prevent peptide bond formation in prokaryotes.

b. Prevent polypeptide elongation in eukaryotes.

c. Prevent binding of tRNA in eukaryotes.

d. Prevent binding of tRNA in eukaryotes.

e. Cause misreading of mRNA in 70S ribosomes.

Back 6

e. Cause misreading of mRNA in 70S ribosomes.

Front 7

The substrate for transpeptidase used to synthesize peptidoglycan is shown in Figure 20.5. Which of the drugs shown would inhibit peptidoglycan synthesis?

Select one:

a. a

b. b

c. c

d. d

Back 7

d

Front 8

The structures of the influenza drug Tamiflu and sialic acid, the substrate for influenza virus's neuramidase, are shown in Figure 20.6. What is the method of action of Tamiflu?

Select one:

a. Inhibits cell wall synthesis

b. Prevents synthesis of virus spikes

c. Inhibits synthesis of neuramidase

d. Competitive inhibition

e. Inhibits plasma membrane synthesis

Back 8

Competitive inhibition

Front 9

In the presence of penicillin, a cell dies because

Select one:

a. It undergoes osmotic lysis.

b. It lacks a cell membrane.

c. It lacks a cell wall.

d. It plasmolyzes.

e. Its contents leak out.

Back 9

It undergoes osmotic lysis.

Front 10

In what way are semisynthetic penicillins and natural penicillins alike?

Select one:

a. Both are broad spectrum.

b. Both are based on β-lactam.

c. Both are bactericidal.

d. Both are resistant to penicillinase.

e. Both are resistant to stomach acids.

Back 10

Both are based on β-lactam.

Front 11

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

Select one:

a. Bacitracin.

b. Griseofulvin.

c. Polymyxin B.

d. Echinocandins.

e. Azole antibiotics.

Back 11

e. Azole antibiotics.

Front 12

Mebendazole is used to treat cestode infections. It interferes with microtubule formation; therefore, it would NOT affect

Select one:

a. Helminths.

b. Bacteria.

c. Human cells.

d. Fungi.

e. Protozoa.

Back 12

bacteria

Front 13

More than half of our antibiotics are

Select one:

a. Produced by bacteria.

b. Produced by Fleming.

c. Produced by fungi.

d. Synthesized in laboratories.

e. Produced by eukaryotic organisms.

Back 13

produced by bacteria

Front 14

Most of the available antimicrobial agents are effective against

Select one:

a. Bacteria.

b. Protozoa.

c. Fungi.

d. Viruses.

e. All of the above.

Back 14

bacteria

Front 15

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

Select one:

a. Gram-negative bacteria.

b. Mycobacterium tuberculosis.

c. Viruses.

d. Gram-positive bacteria.

e. Helminths.

Back 15

e. Helminths.

Front 16

Penicillin was considered a "miracle drug" for all of the following reasons EXCEPT

Select one:

a. It doesn't affect eukaryotic cells.

b. It inhibits gram-positive cell wall synthesis.

c. It was the first antibiotic.

d. It has selective toxicity.

e. It kills bacteria.

Back 16

the first antibiotic

Front 17

Protozoan and helminthic diseases are difficult to treat because

Select one:

a. Their cells are structurally and functionally similar to human cells.

b. They don't reproduce.

c. They don't have ribosomes.

d. They have more genes than bacteria.

e. They replicate inside human cells.

Back 17

a. Their cells are structurally and functionally similar to human cells.

Front 18

The antibiotic actinomycin D binds between adjacent G-C pairs, thus interfering with

Select one:

a. Peptide bond formation.

b. Transcription.

c. Plasma membrane function.

d. Translation.

e. Cellular respiration.

Back 18

transcription

Front 19

The antimicrobial drugs with the broadest spectrum of activity are

Select one:

a. Aminoglycosides.

b. Macrolides.

c. Lincomycin.

d. Chloramphenicol.

e. Tetracyclines.

Back 19

e. Tetracyclines.

Front 20

Use of antibiotics in animal feed leads to antibiotic-resistant bacteria because

Select one:

a. Bacteria from other animals replace those killed by the antibiotics.

b. The antibiotics kill susceptible bacteria, but the few that are naturally resistant live and reproduce, and their progeny repopulate the host animal.

c. The few surviving bacteria that are affected by the antibiotics develop immunity to the antibiotics, which they pass on to their progeny.

d. The antibiotics cause new mutations to occur in the surviving bacteria, which results in resistance to antibiotics.

e. The antibiotics persist in soil and water.

Back 20

b. The antibiotics kill susceptible bacteria, but the few that are naturally resistant live and reproduce, and their progeny repopulate the host animal.

Front 21

Which of the following antibiotics causes misreading of mRNA?

Select one:

a. Tetracyclines bind with 30S subunit

b. Chloramphenicol inhibits peptide bonds at 50S subunit

c. Oxazolidinone prevents formation of 70S ribosome

d. Streptogamin prevents release of peptide from 70S ribosome

e. Aminoglycoside changes shape of 30S units

Back 21

. Aminoglycoside changes shape of 30S units

Front 22

Which of the following antibiotics does NOT interfere with cell wall synthesis?

Select one:

a. Natural penicillins

b. Cephalosporins

c. Semisynthetic penicillins

d. Macrolides

e. Vancomycin

Back 22

Macrolides

Front 23

Which of the following antibiotics is NOT bactericidal?

Select one:

a. Polyenes

b. Cephalosporins

c. Rifampins

d. Penicillin

e. Aminoglycosides

Back 23

. Polyenes

Front 24

Which of the following antimicrobial agents is recommended for use against fungal infections?

Select one:

a. Amphotericin B

b. Cephalosporin

c. Polymyxin

d. Bacitracin

e. Penicillin

Back 24

Amphotericin B

Front 25

Which of the following does NOT constitute an advantage of using two antibiotics together?

Select one:

a. It can prevent drug resistance.

b. It lessens the toxicity of individual drugs.

c. It allows treatment to be provided prior to diagnosis.

d. Two are always twice as effective as one.

e. All of the above are advantages.

Back 25

d. Two are always twice as effective as one.

Correct

Front 26

Which of the following drugs does NOT act by competitive inhibition?

Select one:

a. Streptomycin

b. Isoniazid

c. Tetracycline

d. Ethambutol

e. Sulfonamide

Back 26

Streptomycin

Front 27

Which of the following organisms would most likely be sensitive to natural penicillin?

Select one:

a. L forms

b. Mycoplasma

c. Penicillium

d. Streptococcus pyogenes

e. Penicillinase-producing Neisseria gonorrhoeae

Back 27

Streptococcus pyogenes

Front 28

Which of these antimicrobial agents has the fewest side effects?

Select one:

a. Streptomycin

b. Tetracycline

c. Chloramphenicol

d. Erythromycin

e. Penicillin

Back 28

e. Penicillin