This is a lesson which meets specification points within the WJEC GCSE ‘The Sciences’ Double Award (2026) spec, specifically from Unit 1.4 - Interdependence of Organisms (Physics).

The lesson starts with an overview of the key vocabulary which students will be learning and using this lesson. Students can stick their key word lists into their books before the lesson begins.

First of all students are asked to consider why not all of the light that falls onto a plant will be used in photosynthesis. Students can think > pair > share their ideas in their books. Once complete the following slide goes through the possible ways in which light energy can be lost before it used to make new plant biomass. Students will listen and then need to fill in the blanks on a paragraph detailing these processes. Once this task is complete students can self-assess their work.

Students are then shown a simple food chain and asked to think about how biomass could be lost at each stage in the food chain. Pupils can discuss their ideas and create a mind map in their books, why isn’t all of the biomass from trophic level passed on to the next trophic level? The next slide reveals some of these reasons, pupils can check their work against the answers.

Pupils will then be given a worksheet detailing energy loss and energy transfer criteria, students need to use this information to annotate a food chain to show how energy is lost and how much is transferred to the next trophic level. There are a number of ways in which they may do this but there is a sample answer provided to demonstrate how the student could have completed their work.

The last part of the lesson looks at efficiency of energy transfer, pupils will be shown the efficiency calculation and a worked example. Pupils can write the calculation into their books and then use this to answer a set of questions. Once complete pupils can self-assess their work.

The plenary task is for pupils to turn to the back of their books and write three summary sentences on what they have learned this lesson.

All resources are included at the end of the presentation. Thanks for looking, if you have any questions please let me know in the comments section and any feedback would be appreciated :)