Water Movement in Plants
- Water is transported through a plant, from its point of absorption (the root hairs of the roots) up the xylem tissue in the stem, to the leaves of the plant, where water vapour evaporates through a process called transpiration (evaporation of water vapour from the stem and leaves)
- This is a passive process, as the movement of water is being driven by the evaporation of water vapour occurring from the leaves
- Roughly 99% of the water absorbed is lost to transpiration
- There is a gradient in water potential (Ψp) between the root hair cell (high water potential) and the leaves (low water potential), that plants rely on to move water up the plant
- Water also moves between cells from a high water potential to low water potential
An overview of the movement of water through a plant, from a high water potential in the roots to a low water potential in the leaves
Exam Tip
Remember that pure water has a water potential of 0, so the more negative the water potential is the lower its water potential is.