International A Level Biology / Immunity

Core practical 14: the effect of antibiotics on bacteria

Edexcel International A Level Biology (YBI11), chapter 18: Immunity, specification point 6.14. Part of the full course.

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The disc diffusion method compares how antibiotics inhibit bacterial growth by measuring clear zones on agar. Zone size helps compare antibiotics, but it does not show which one will work best in a patient.

More lessons in Immunity

• Non-specific responses: inflammation, lysozyme and interferon
• Phagocytosis
• Antigens, antibodies and antigen-presenting cells
• The specific response: B cells and antibodies
• The specific response: T helper, T killer and T memory cells
• Natural, artificial, active and passive immunity
• The evolutionary race between pathogens and hosts
• Antibiotics: bacteriostatic and bactericidal
• Antibiotic resistance and hospital-acquired infections