1.10 Exchaning materials

• What is the learning objective of B1.10 Exchanging materials?

  Understand surface area to volume ratio
• Why do large multicellular organisms need special systems for exchanging materials?

  To efficiently exchange materials with the environment
• How does surface area to volume ratio vary with organism size?

  • Smaller organisms have a larger SA:V ratio
  • Larger organisms have a smaller SA:V ratio
  • Affects material exchange efficiency
• What processes do single-celled organisms use to exchange materials?

  Diffusion, osmosis, and active transport
• Why is the surface area to volume ratio important in biology?

  It affects substance exchange and energy acquisition
• What happens to the surface area to volume ratio as objects get bigger?

  It falls as objects increase in size
• How does a smaller surface area to volume ratio affect diffusion?

  Diffusion distances become longer, slowing exchange
• What challenges do larger organisms face regarding material exchange?

  Gases and nutrients can't reach all cells quickly
• What adaptations improve the efficiency of exchange surfaces?

  • Large surface area for exchange
  • Thin membranes for short diffusion paths
  • Efficient blood supply in animals
  • Steep concentration gradients maintained
• What is a unique adaptation of the Australian thorny devil for water absorption?

  Large surface area and blood vessels under skin
• Why can't human cells rely on simple diffusion for material exchange?

  Human surface area to volume ratio is too low
• How have blood vessels evolved in humans for material exchange?

  To provide a large surface area for exchange
• What role do gills play in fish for material exchange?

  They facilitate gas exchange with water
• How do fish maintain concentration gradients for gas exchange?

  By pumping water over their gills
• What adaptation do plant roots have for efficient water uptake?

  Large surface area enhanced by root hair cells
• How do plant leaves facilitate gas and solute exchange?

  By maintaining steep concentration gradients and large surface area
• What are the key points regarding exchange in simple-celled and multicellular organisms?

  • Simple-celled organisms have a large SA:V ratio
  • Multicellular organisms have adaptations for efficient exchange
  • Exchange surfaces in animals have abundant blood supply
• What is the importance of maintaining steep concentration gradients in exchange surfaces?

  It enhances the efficiency of material exchange
• What is the relationship between surface area to volume ratio and diffusion paths?

  A larger ratio means shorter diffusion paths
• How does the structure of alveoli aid in gas exchange?

  They provide a large surface area and rich blood supply
• How do adaptations in the small intestine relate to material exchange?

  They increase surface area for nutrient absorption
• What is the role of stomata in plant leaves?

  They facilitate gas exchange and maintain gradients