AQA Trilogy GCSE (9-1) Biology – Exchanging Materials
This resource is designed to meet specification points in the new AQA Trilogy Biology ‘Cells’ SoW.
This lesson begins with pupils shown a picture of an amoeba and one of a polar bear, they will need to discuss the difference between the organisms in terms of how they take in oxygen from their environment. Once you have shared a few ideas from the pupils with the class you can show the pupils the difference between the two organisms - amoeba can rely on simple diffusion whereas larger multicellular organisms need specialised exchange surfaces.
Pupils are then shown three examples of exchange surfaces - alveoli, small intestine, and leaves of plants - they will need to think about how these structures might be adapted to exchange materials efficiently. You could have a short class discussion to develop these ideas.
Once you have again discussed these factors with the class you can reveal the next slide which outlines the four main features of an efficient gas exchange surface.
Pupils will then be given a worksheet and they will need to move around the room reading posters of information about villi and alveoli to complete the worksheet. This should take approximately 20 minutes, once finished pupils can peer-assess their work using the answers provided with the PowerPoint presentation.
The plenary is an ‘Exit Card’ pupils will complete and pass to you on the way out of the door, this requires pupils to write down 3 key words, one fact and a question to test their peers knowledge of what they have learnt about in the lesson today.