cell transport

• What is diffusion?

  The spread of particles from high to low concentration
• What is the direction of net movement in diffusion?

  From high concentration to low concentration
• Is energy required for diffusion?

  No, energy is not required
• How does the concentration gradient affect the rate of diffusion?

  A steeper gradient increases the rate of diffusion
• How does temperature affect the rate of diffusion?

  Higher temperature increases the rate of diffusion
• What role does surface area play in diffusion?

  Larger surface area increases the rate of diffusion
• What is osmosis?

  The diffusion of water through a partially permeable membrane
• What is the direction of water movement in osmosis?

  From dilute solution to concentrated solution
• Is energy required for osmosis?

  No, energy is not required
• What is active transport?

  The movement of particles using energy from respiration
• What is the direction of movement in active transport?

  From dilute solution to concentrated solution
• Is energy required for active transport?

  Yes, energy is required
• What are the adaptations for effective exchange surfaces?

  • Large surface area
  • Thin membrane
  • Good blood supply
• What is the function of villi in the small intestine?

  For absorbing nutrients
• What features of villi aid in nutrient absorption?

  Good blood supply, thin wall, large surface area
• What is the function of alveoli in the lungs?

  For gas exchange
• What features of alveoli enhance gas exchange?

  Large surface area, moist, one cell thick
• What is the function of fish gills?

  For gas exchange
• What structural features of fish gills aid in gas exchange?

  Stacks of thin filaments and capillary network
• What is the function of root hair cells?

  For uptake of water and minerals
• What adaptations do root hair cells have for absorption?

  Lots of mitochondria and large surface area
• How do root hair cells take in minerals?

  By active transport using energy