3.1 surface area to volume ratio

• What is the relationship between the size of an organism and its surface area to volume ratio?

  The smaller the organism, the larger the surface area to volume ratio and vice versa.
• How do larger organisms adapt to facilitate exchange with their low surface area to volume ratio?

  • changed body shape
  • development of specialised cells, tissues, organs and systems e.g. gas exchange system, circulatory system, lymphatic system, urinary system, xylem and phloem
• What is the relationship between the surface area to volume ratio of an organism and it a metabolic rate?

  Smaller organisms have a greater surface area to volume ratio so they lose more heat, meaning they have to use up more energy to maintain their body temperature so have higher metabolic rates.