Surface Area to Volume ratio

• What is the equation to calculate SA:V ratio?

  Surface area / Volume
• What happens to the SA:V ratio as cells get larger and why?

  SA:V ratio decreases as cells get larger

  Due to a higher SA and a higher V, making a lower ratio
• How do single cell organisms exchange gases between them and their environment and why?

  Simple diffusion across the membrane

  Due to a large SA:V ratio
• How do large organisms exchange gases with their environment and why?

  Using specialised systems to compensate, such as lungs in humans, also have specialised transport systems to carry molecules around the body e.g blood.

  Due to a small SA:V ratio