exchange surfaces

• describe surface area and volume of single celled organism

  high surface area to volume ratio
• describe surface area and volume of multi cellular organism

  low surface area to volume ratio
• describe function of exchange surfaces

  provide efficient substance exchange for multi cellular organisms due to low surface area to volume ratio
• give examples of exchange surfaces

  alveoli in lungs, villi in small intestine, gills in fish and root hair cells in plants
• describe function of alveoli in lungs

  efficient gas exchange of oxygen and carbon dioxide
• give adaptations of alveoli in lungs for function

  large surface area, moist lining, thin walls and good blood supply
• describe function of villi in small intestine

  efficient absorption of digested substances into blood
• give adaptation of villi in small intestine for function

  large surface area, single celled walls and good blood supply
• describe function of gills in fish

  efficient gas exchange in water of oxygen and carbon dioxide
• give adaptations of gills in fish for function

  large surface area, thin surface cells, good blood supply and opposite substance flow
• describe function of root hair cells in plants

  efficient absorption of water and mineral ions from soil for plant growth
• give adaptations of root hair cells in plants for function

  large surface area and lots of mitochondria
• describe function of leaves

  efficient gas exchange of carbon dioxide, oxygen and water vapour into and out of plant
• give adaptations of leaves in plants

  large surface area and guard cells
• give ways to increase effectiveness of exchange surfaces

  increase surface area, thin membrane, good blood supply and ventilation