Transpiration and Transolcation

• A xylem cell is made up of of dead cells joined together with no end walls between them. They have thick walls strengthened with lignin and allow one-way transport of water and minerals only.
• Xylem cells provide water to cells to keep them turgid and allow photosynthesis to occur. They transport mineral ions to leaves and are found in the stem.
• Phloem cells are long, living cells that carry dissolved sugars. They are found in stem and transport substances in both directions. The cells have end walls with small holes to allow substances to flow through.
• Translocation is the movement of dissolved sugars from the leaves to the rest of the plant through the phloem. It moves sugars made in the leaves during photosynthesis to other parts of the plant. This allows for respiration, growth and the storage of glucose.
• Water is lost through the stomata by evaporation. This pulls water up from the roots through the xylem and is called transpiration. The constant movement of water up and down the plant is called the transpiration stream.
• Label the Diagram

  A) Reservoir

  B) Air Bubble

  C) Capillary Tube

  D) Beaker of Water

  E) Cut Shoot

  F) Volume Scale

  
• In a potometer investigation, as the plant takes up water, the air bubble moves up the scale.