Surface Area To Volume Ratio

• Describe the relationship between the size of an organism and its SA:V ratio

  Smaller organisms have high SA:V ratios

  Larger organisms have low SA:V ratios
• What adaptations do some organisms have for exchange (in terms of SA:V ratio)?

  Flattened shape so small diffusion distance

  Specialised exchange surfaces with surface areas
• What is the relationship between SA:V ratio and metabolic rate?

  Smaller organisms ---> higher SA:V ratio ---> higher metabolic rate.

  
  

  In endothermic and exothermic animals, metabolic rate is inversely proportional to size.