Biology unit 8

• xylem vessel?


  transport water and minerals from the roots to the stem and leaves
• phloem vessel?

  transports sucrose and amino acids made by the plant from photosynthesising leaves to non-photosynthesising regions in the roots and stem
• xylem cell contents?


  no cell contents just a continuous column of water
• what are xylem walls thickened with?

  lignin, for support
• root hair cell?


   single-celled extensions of epidermis cells in the root
• where are root hair cells found?

  they grow between soil particles and absorb water and minerals from the soil
• how does water enter the root hair cells?

  osmosis
• how do mineral ions enter the root hair cells?

  active transport
• what is the pathway of water when it goes into a plant?

  root hair cell then root cortex cells then xylem then leaf mesophyll cells
• why does water go into a plant?

  to replace the water that has been lost due to transpiration
• transpiration?


  loss of water vapour from plant leaves by evaporation of water at the surfaces of the mesophyll cells followed by diffusion of water vapour through the stomata
• transpiration functions??


  transporting mineral ions, providing water to keep cells turgid in order to support the structure of the plant, providing water to leaf cells for photosynthesis, keeping the leaves cool 
• where does evaporation take place?

  from the surfaces of spongy mesophyll cells
• Water molecules are attracted to each other by

  cohesion
• translocation?


  The transport of sucrose and amino acids in the phloem, from regions of production to regions of storage or use
• xylem process?


  transpiration
• phloem process?


  translocation