surface area to volume ration

• What concept explains why multicellular organisms need exchange surfaces?

  Surface area to volume ratio
• Why do multicellular organisms require a transport system?

  To efficiently transport gases and nutrients
• How do gills function in fish for gas exchange?

  They transport oxygen from water into the bloodstream
• What is the process by which molecules move in and out of cells?

  Diffusion
• What is the surface area to volume ratio?

  It compares the surface area of an object to its volume
• What is the surface area of a cube with a side length of 1 mm?

  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
• What is the surface area of a cube with a side length of 2 mm?

  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 a cube with a side length of 2 mm?

  1. 1
• What is the surface area of a cube with a side length of 3 mm?

  54 square mm
• What is the volume of a cube with a side length of 3 mm?

  27 cubic mm
• What is the surface area to volume ratio of a cube with a side length of 3 mm?

  1. 1
• What problems do multicellular organisms face regarding gas exchange?

  • Surface area insufficient for volume
  • Cells far from surface can't get enough oxygen
• How do animals solve gas exchange problems?

  1. Special structures for gas exchange (e.g., lungs)
  2. Transport systems to carry gases around the body
• What adaptations do fish gills have for efficient gas exchange?

  • Massive surface area from filaments
  • Thin membrane for short diffusion pathway
  • Efficient blood supply to maintain concentration gradient
• What is the role of deoxygenated blood in fish gills?

  It passes into the filaments for oxygen uptake
• What happens to oxygenated blood in fish gills?

  It returns to the body after gas exchange
• What is a key fact about diffusion related to surface area to volume ratio?

  • Higher surface area to volume ratio enhances diffusion efficiency
• What is the significance of the concentration gradient in gas exchange?

  • Maintains efficient diffusion of gases