GCSE Biology: Factors Affecting Diffusion Lesson – Temperature, Concentration Gradient and Surface A

Help students explain how changing conditions affect diffusion. This lesson connects particle movement and concentration gradients with biological adaptations that increase the rate of exchange.

Learning Objectives

• Identify factors affecting the rate of diffusion.
• Explain the effects of temperature and concentration gradient.
• Explain how surface area and diffusion distance affect exchange.
• Predict how changing conditions will affect diffusion.
• Apply understanding to biological examples.

Lesson Overview

Students use the particle model to explain changes in diffusion rate, moving beyond recalling that a factor makes diffusion faster or slower.

The planned sequence explores temperature, concentration gradient, surface area and diffusion distance. Prediction and explanation tasks encourage students to justify their answers using particle movement and the conditions at an exchange surface.

Biological examples connect these principles with adaptations that support efficient exchange.

Suitable For

KS4 students studying GCSE Biology or the Biology component of GCSE Combined Science.

What’s Included

• PowerPoint lesson presentation
• Particle-model explanations and diagrams
• Comparisons of factors affecting diffusion
• Prediction and explanation activities
• Biological application questions