Four paper discs, each soaked in a different antibiotic, are placed on a lawn of one species of bacterium. After incubation the clear zones have diameters of 8 mm, 14 mm, 6 mm and 19 mm. Which disc contained the most effective antibiotic?
The disc with the 14 mm clear zone
The disc with the 8 mm clear zone
The disc with the 6 mm clear zone
The disc with the 19 mm clear zone
139 exam-style questions on AQA GCSE Biology 1.1 Cell structure, covering 1.1.1 Eukaryotes and prokaryotes, 1.1.2 Animal and plant cells, 1.1.3 Cell specialisation, 1.1.4 Cell differentiation, 1.1.5 Microscopy, and 1.1.6 Culturing microorganisms. Each one has a worked solution and a mark scheme showing where the marks go.