Surface area to volume ratio

• Relationship between organisms size and their surface area

  The larger the organism the lower the surface area to volume ratio will be
• How does the surface area to volume ratio affect the transport of molecules

  The lower the surface area:volume the further the distance molecules need to travel

  Once distance becomes too great diffusion alone is not sufficient to transport molecules
• Why do larger organisms require specialised exchange surfaces

  Exchange surfaces provide larger extra surface area adapted for exchanging substances.

  This makes up for the small surface area:volume
• Why do larger organisms require mass transport systems

  Diffusion alone is not sufficient to quickly transport substances long distances