Transport in plants

• how is leaf shape an adaptation of xerophytes?

  • conifers’ leaves are reduced to thin needles, greatly reducing SA:V ration minimising water loss in transpiration
  • curled leaves - confines all stomata within a micro environment of still, humid air to reduce water vapour loss
• how is salt concentration inside leaves an adaptation of xerophytes?

  • higher salt concentration inside leaf so lowers water potential inside plant cells so water will be retained
  • low water potential reduces evaporation of water from cells surfaces as the water potential gradient between the cells and the leaf air spaces are reduced
• how is leaf loss an adaptation of xerophytes?

  • losing leaves when water is now available to prevent water loss through transpiration through the leaves
• what are root adaptations in xerophytes?

  • long tap roots growing deep into the ground can penetrate several meters - can access water a long way below surface
  • a mass of widespread, shallow roots with a large SA to absorb any available water before a rain shower evaporates
• what is a hydrophyte?

  plants with adaptations that enable them to survive in very wet habitats or submerged or at the surface of water
• what is an example of a hydrophyte?

  water lily
• what problems must hydrophytes overcome?

  gas exchange - stomata usually on bottom of leaf but can’t be because water would block stomata