2.52: Describe the Role of Xylem in Transporting Water and Mineral salts from the Roots to the Other Parts of the Plant

XYLEM: Consists of Elongated Dead cells, Arranged as a Continuous vessel Where the Dead Cells are Arranged End to End

• Contains No Cytoplasm so is Impermeable to water
• Has Tough Walls containing a Lignin
• Transports Water and Mineral Ions from the Roots to Other Parts of the Plants by Transpiration

Diagram:

                  

XYLEM AND TRANSPIRATION:

TRANSPIRATION: Evaporation of Water from the Surface of the Plant

TRANSPIRATION

Diagram Showing the Process of Transpiration in Plants

PROCESS: Water Vapours will Pull on Each Other Up the Xylem Vessels as they Are Cohesive (Vapours Sticks and Travels Together) Water Move through the Spongy Mesophyll Cells by Osmosis and will Form Water Vapours and Evaporate, Diffusing Out of the Stomata of the Leaf Water will be Continuously Drawn Up the Xylem to Replace the Water that is Lost, Creating a Transpiration Stream (Like a Drinking Straw with a Flow of water and Dissolved Minerals from the Roots to the Leaves)

FUNCTIONS: Constant Uptake and Transport of Mineral Ions (E.g Nitrates for Amino Acids to Build Protein) Providing Water to Keep Cells Turgid to Make them Bigger and Stronger to Support Upward Growth of Plant Provide Water to Photosynthesizing Cells in Leaves to Conduct Photosynthesis Keep the Leaves Cool by Evaporative Cooling (Maintains Optimum Temperature of Enzymes so Temperatures Do Not Get Too Hot)