Biology 9700 · AS & A Level · Antibiotics

Antibiotics — practice question

If bacteria are cultured in a Petri dish with discs that contain antibiotics, zones of inhibition of bacterial growth will form. The chart presents the diameters of the zones of inhibition when a species of bacteria was incubated on five separate agar plates, each with a disc carrying a different antibiotic. Which conclusions can be drawn about the most and least effective antibiotics for this species of bacteria?

  • Amost effective antibiotic 3; least effective antibiotic 2
  • Bmost effective antibiotic 4; least effective antibiotic 3
  • Cmost effective antibiotic 3; least effective antibiotic 1
  • Dmost effective antibiotic 2; least effective antibiotic 3

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