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Why organisms exchange substances

Why organisms exchange substances

Cells need oxygen, water, dissolved food molecules and mineral ions, while waste substances such as carbon dioxide and urea must be removed. An exchange surface is a boundary across which these substances move between an organism and its environment.

8.1 Exchange surfaces and diffusion Lesson

  1. GCSE
  2. /Biology
  3. /8.1 Exchange surfaces and diffusion

Step-by-step lessons on Edexcel GCSE Biology 8.1 Exchange surfaces and diffusion, covering 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. Each one builds up to exam-style questions. Start with the foundational topics and build up to the higher-tier material.

Lessons