GCSE Biology - Surface Area to Volume Ratio (2026/27 exams)

⭐️ Check out our website https://www.cognito.org/ ⭐️ ** WHAT'S COVERED ** 1. The concept of surface area to volume ratio. 2. The importance of SA:V ratio for the exchange of substances via diffusion in organisms. How single-celled organisms exchange substances. Why large multicellular organisms need specialised systems. 3. How surface area and volume change as an organism gets larger. 4. Calculating surface area, volume, and the SA:V ratio using cube examples. 5. Why larger organisms cannot rely solely on diffusion across their outer surface. The need for specialised exchange surfaces. The need for transport systems. ** CHAPTERS ** 0:00 Intro to Surface Area to Volume Ratio 0:11 Why SA:V Ratio Matters for Organisms 0:43 Needs of a Single-Celled Organism 1:15 Surface Area vs Volume Explained 1:52 Calculating Surface Area to Volume Ratio 2:11 Calculating Surface Area of a Cube 2:42 Calculating Volume of a Cube 2:59 Calculating the SA:V Ratio (Examples) 3:45 Comparing SA:V Ratios 4:20 Applying SA:V Ratio to Bacteria & Humans 4:49 Specialised Exchange Surfaces & Transport Systems 5:24 Diffusion Distances and Size 6:36 Summary: Why Larger Organisms Need Specialised Systems ** PLAYLISTS **    • GCSE Maths (9-1)      • GCSE Biology (9-1)      • GCSE Chemistry (9-1)      • GCSE Physics (9-1)      • A-Level Biology   #GCSE #Biology #study #revision #school #exam #AQA #OCR #Edexcel #IGCSE #IB #AP