The introductory presentation for this unit is here: GCSE Geography ecology
If you were not in Year 9 Geography but joined GCSE Geography without doing the subject in Key Stage 3 you should catch up with the topic of Biomes. Use this link to the BBC Bitesize pages on the topic.
The first example of a biome (for case study purposes) is the tropical rainforest. The National Geographic (2017) documentary lasts 45 minutes. If you did not take sufficient notes in the lesson, please watch it again at home and review your notes.