transport systems

• need for plant transport systems

  -metabolic demands= internal and underground cells don't photosynthesise, so glucose needs to be transported to those cells.

  -size= plants grow continuously throughout their lives, so need effect transport systems to move substances from the root to leaves.

  -surface area= leaves adapted to have a large SA but stems, trunks and roots have a small SA, so they can't rely on diffusion alone.
• dicotyledonous plants

  = make seeds that contain two cotyledons, organs that act as food stores for developing embryo plant and form the first leaves when the seed germinates.

  • herbaceous dicots= with soft tissues and a relatively short life cycle.
  • woody dicots= have hard, lignified tissues and have a long life cycle.
• herbaceous dicots 


  = made up of two main types of transport vessels, the xylem and the phloem.

  • these transport tissues are arranged together in vascular bundles in the leaves, stems and roots.
  • stem= vascular bundles are around the edge gives strength+ support.
  • roots= vascular bundles are in the middle, help the plant withstand tugging stains from when stems and leaves are blown in the wind.
  • leaves= the midrib of a leaf is the main vein carrying the vascular tissue, helps support the leaf.