The Need for Exchange
The Need for Exchange
To stay alive, every living cell must continuously take in useful substances and remove metabolic waste. Helpful substances include oxygen, glucose, and water. Waste substances that must be excreted include carbon dioxide and urea.
Step-by-step lessons covering Edexcel GCSE Biology 8.1 Exchange surfaces and diffusion for Foundation and Higher tier. Each lesson breaks down 8.1.1 Introduction to exchange and transport, 8.1.2 Alveoli adapted for gas exchange, 8.1.3 Factors affecting rate of diffusion, and 8.1.4 Rate of diffusion using Fick's law, then works through exam-style questions in Paper 1 and Paper 2 format. Start with the foundational topics and build up to the higher-tier material.