surface area to volume ratio

• What concept explains why multicellular organisms require exchange surfaces and a transport system?

  Surface area to volume ratio
• How do gills increase the rate of gas transport in fish?

  They provide a large surface area for gas exchange
• What is the process by which molecules move in and out of cells?

  Diffusion
• What is the surface area to volume ratio of a single-celled organism like an amoeba?

  It has a high surface area to volume ratio
• If an organism shaped like a cube has a side length of 1 mm, what is its surface area?

  6 square mm
• What is the volume of a cube with a side length of 1 mm?

  1 cubic mm
• What is the surface area to volume ratio of a cube with a side length of 1 mm?


  1. 1
• For an organism with a side length of 2 mm, what is the surface area?

  24 square mm
• What is the volume of a cube with a side length of 2 mm?

  8 cubic mm
• What is the surface area to volume ratio of an organism with a side length of 2 mm?


  1. 1
• What is the surface area to volume ratio of an organism with a side length of 3 mm?

  1. 1
• Why do multicellular organisms face challenges with gas exchange?

  Their surface area is not large enough for their volume
• How do animals solve the problem of gas exchange?

  By having specialized structures and a transport system
• How do fish obtain oxygen from water?

  Oxygen-rich water passes over their gills
• What role do gill filaments play in gas exchange?

  They provide a large surface area for diffusion
• What adaptations do gill filaments have to enhance diffusion?

  They have a large surface area, thin membranes, and an efficient blood supply
• Why is a high concentration gradient important for gas exchange in gills?

  It ensures efficient diffusion of oxygen into the blood
• What are the key adaptations of gills for gas exchange?

  • Large surface area
  • Thin membranes for short diffusion pathway
  • Efficient blood supply to maintain concentration gradient
• What is the relationship between surface area to volume ratio and organism size?

  • As organisms increase in size, the surface area to volume ratio decreases sharply
  • Larger organisms face challenges in gas exchange due to insufficient surface area