What you'll learn
How animals exchange and transport substances.
Key ideas
- Surface-area-to-volume ratio and the need for exchange surfaces.
- Alveoli and gas exchange; the circulatory system and blood.
Exam tips
- Link adaptations (thin walls, large surface area) to function.
- Explain why large organisms need transport systems.
Common mistakes
- Forgetting adaptations of exchange surfaces.
- Confusing arteries and veins.