9.1 transport systems in dicotyledonous plants

    Cards (29)

    • name three reasons why multicellular plants need transport systems
      • metabolic demands
      • size
      • surface area to volume ratio
    • explain why transport systems are need to meet the metabolic demands of multicellular plants
      • not all parts of the plant photosynthesise but still need glucose, oxygen and hormones transported to them
      • and waste products need to be removed
    • explain why the size of a plant means a transport system is needed
      to transport substances from the roots of very large plants to the top of of the plant eg. leaves
    • why does a surface area to volume ratio matter when talking about transport systems for plants
      larger plants have a low surface area to volume ratio so they can rely just on diffusion to supply their cells with everything they need so transport system is needed
    • what is a series of transport vessels through stem, roots and leaves called
      vascular system
    • what two transport vessels is the vascular system made out of
      xylem and phloem
    • in stem the vascular bundles are around the edge to give strength and support
    • label stem
    • label ts root cell
    • label ts of leaf
    • is the xylem a living or non living tissue
      non living tissue
    • what two main functions does the xylem have in a plant
      • transport of water and mineral ions
      • support
    • what are the two main cells in the vessels
      xylem vessels and xylem parenchyma
    • what cell packs around the xylem vessels
      xylem parenchyma cells
    • what do xylem parenchyma cells do
      store food and contain tannin deposits
    • what are tannin deposits for
      bitter tasting chemicals which protect plant tissues from being eaten by herbivores
    • what are xylem fibres
      they are long cells with lignified secondary walls that provide extra mechanical strength but do not transport water
    • what does lignin do
      helps reinforce the xylem vessels so they do not collapse under transpiration pull
    • is the phloem living or non living tissue
      living tissue
    • what does the phloem do
      transports food in the form of organic solutes around the plants from leaves
    • what does the phloem supply to the cells
      sugars and amino acids needed for cellular respiration and synthesis of other useful molecules
    • in which direction is the flow of materials in the phloem
      both up and down
    • in which direction is the flow of water in the xylem
      up the plant from roots to leaves
    • what are the main transporting vessels of the phloem
      sieve tube elements
    • phloem
    • are phloem tubes liginified
      no
    • what are closely linked to sieve tube elements
      companion cells
    • what are sieve tube elements made of
      cells joined end to end to form a long hollow structure
    • what are the plasmodesmata
      microscopic channels through the cellulose cell walls linking the cytoplasm between sieve tube elements and adjacent companion cells