Describe The Mechanism Of Water Movement In Xylem?


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It is common sense that water enters a plant through its roots deep in soil. We also know that it can also enter through the tiny hairs that appear on the plant's stems however, the next stage of the waters journey is the seemingly complex part. This requires the water to then travel throughout the entire plant until it reaches the green leaves and it does so through cells called xylem.
  • These cells are basically transport cells that act like a highway for the water to travel to its necessary areas. They are long empty tubes tightly fitted together and joined end to end, containing lignin that prevents them from collapsing.
  • Movement through xylem takes place after osmosis which refers to the intake of mineral salts and water by the soil and into the roots. It then enters the xylem vessels through the Pericycle.
  • Water leaves the plants through evaporation in the pores of the leaves, also known as transpiration. This is a key element to the movement of water in the xylem vessels that stem the whole length of the plant. As this takes place, it causes the tubes to contract and move the water from the roots upwards to the leaves where the water that is not evaporated, is used in photosynthesis.
  • The result of the water evaporation on the xylem tubes is called the transpirational pull.
The water moves smoothly through each xylem tube and as water cannot directly be absorbed through the leaves, any water that sits on them can cause more damage than good.

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