Water Transport in the Xylem (AQA A Level Biology) : Revision Note

Water & Mineral Ion Transport: Pathways & Mechanisms

• Within a plant, mineral ions and organic compounds (e.g. sucrose) are transported while dissolved in water. The dissolved mineral ions are transported in the xylem tissue and the dissolved organic compounds are transported in the phloem tissue

• The plant roots are responsible for the uptake of water and mineral ions and can have root hairs to increase the surface area for absorption of the substances

• The uptake of water is a passive process and occurs by osmosis

• The uptake of minerals can be passive or active and occurs by diffusion or active transport respectively

• Plants must take in a constant supply of water and dissolved minerals to compensate for the continuous loss of water via transpiration in the leaves, and so that they can photosynthesise and produce proteins