Water Transport

Root Anatomy

• The cross section of a root contains the Epidermis, Cortex, and Vascular Cylinder from outside to inside

• The Vascular Cylinder is composed of the endoderm, pericycle, xylem, and phloem

Root Transport

• The epidermis of the a root contains Root Hairs that greatly increase the surface area of the root and thus promote the absorption of water

• Cells in the endoderm are selectively permeable to solutes which promotes the osmotic movement of water

• The Casparian Strip in the endoderm restricts the movement of water back into the cortex

Vascular Cylinder

• The vascular cylinder contains the xylem and phloem

• The xylem is composed of dead cells called Tracheids and Vessel Members

Stem Anatomy

• The cross section of the stem contains the Epidermis, Cortexs and Vascular Cylinder like the roots

Stem Transport

• The adhesive and cohesive properties of water that allow this polar molecule to form hydrogen bonds with itself and with other substances promotes movement of water in thin tubes like the xylem

• This process is called Capillarity

Leaf Anatomy

• The cross section of a leaf contains the Cuticle, Epidermis, Palisade and Spongy Mesophylls, and Veins which contain the plants vascular tissue

Leaf Transport: Cohesion-Tension Theory

• Transpiration or the evaporation of water from the surface of leaves places Tension on a column of water molecules existing from the leaf back to the roots