Cards (5)

  • How does an organisms size relate to the surface area to volume ratio?
    The larger the organism, the lower the surface area to volume ratio
  • How does surface area to volume ratio affect transport of molecules?
    The lower the surface area to volume ratio, the further distance molecules need to travel to reach all parts of the organism, so diffusion alone is not sufficient
  • Why do larger organisms require mass transport and specialised gas exchange surfaces?
    • Diffusion distance is greater
    • Metabolic rate is higher
    • Surface area : volume ratio is smaller
  • The characteristics of a mass transport system:
    • Vessels
    • Directional movement
    • Transport medium
    • Maintenance of speed
  • Features of an efficient exchange surface:
    • Large surface area
    • Thin
    • Steep concentration gradient