An engaging lesson presentation and associated worksheet that looks at the use of antibiotics to treat bacterial infections and the raises the issue of the potential over-use of these substances. The lesson begins by getting the students to recognise the difference between three key terms that begin with anti (antibiotics, antivirals, antiseptics). Students will be introduced to the idea that antibiotics are specific to a small range of bacteria and therefore the correct one has to be selected before being prescribed. Moving forwards, students will meet the idea of the zone of inhibition and will understand how the size of this zone can be used as an indicator to the effectiveness of the treatment. Students are shown how to calculate the size of the zone and then are tested on their ability to apply this mathemetical knowledge. Finally, time is taken to look at the links to the topic of natural selection to explain how some bacteria are resistant to certain antibiotics. There are regular progress checks throughout the lesson so that students can assess their understanding.
This lesson has been designed for GCSE students but could be used as an introduction with A-level Biology students who are about to begin the topic of immunity.