3.1 – Osmosis and exchange

Pages 73 – 78 of the CGP revision notes.

Key questions

  • What is the definition of “osmosis”?
  • How does osmosis work?
  • How does osmosis affect cells in water / strong solutions?
  • How would does affect strips of plant material in water / strong solutions?
  • How does active transport differ from diffusion?
  • Give examples of diffusion, osmosis and active transport in plants and animals.
  • How is a leaf adapted to let gases diffuse in and out of cells?
  • Label a diagram of the lungs.
  • Explain the main steps in breathing in / out.
  • How does modern artificial ventilation of the lungs differ from the old “iron lung”??
  • How are the air sacs of the lungs adapted to maximise diffusion?
  • How are the small intestines adapted to maximise diffusion of glucose etc?
  • How is active transport used by root hairs?
  • When / why is active transport used in the intestines?
  • What is the function of xylem / phloem in plants?
  • What causes transpiration? How does it draw water up a plant?