Plants have two different types of transport tissue. Xylem transports water and solutes from the roots to the leaves, phloem transports food from the leaves to the rest of the plant. Transpiration is the process by which water evaporates from the leaves, which results in more water being drawn up from the roots. Plants have adaptations to reduce excessive water loss.
Xylem and phloem
Plants have transport systems to move food, water and minerals around. These systems use continuous tubes called xylem and phloem.
Xylem
Xylem vessels are involved in the movement of water through a plant from its roots to its leaves. Water:
- Is absorbed from the soil through root hair cells
- Is transported through the xylem vessels up the stem to the leaves
- Evaporates from the leaves (transpiration)
Phloem
Phloem vessels are involved in translocation. This is the movement of food substances from the stems to growing tissues and storage tissues.
Xylem and phloem - Higher tier
Diagram showing the cross sections of a xylem and a phloem
Xylem vessels consist of dead cells. They have a thick, strengthened cellulose cell wall with a hollow lumen. On the other hand, phloem consists of columns of living cells.
