Plant Vascular Tissue

1. Plant Vascular Tissue

2. Plant Tissues. Recap. • Three main types of Plant tissue • Dermal • Ground • Vascular

3. Vascular Tissue • The main function is to transport materials around the plant. • Consists of • Xylem • Phloem

4. Lignin • Lignin is a strong complex Carbohydrate • Found in some plant cell walls • It is a strengthening material i.e. Prevents a cell from collapsing • Lignin forms the wood in trees • Lignin is laid down in specific patterns Spiral Reticulate Circular Pitted Scalariform

5. Diagrams Of Lignin Patterns

6. Xylem • Two specialised cell types • Tracheid cells • Vessel cells Xylem tissue transports water and mineral salts up the plant i.e. From the roots to the tip. Xylem can also give mechanical support due to lignification of its cells.

7. Xylem Tracheids • Long, tapering, lignified dead cells • Water flows in at the bottom and out the top through pits.

8. Xylem Vessels • A number of cells joined end to end • They have no end walls so together form a long continuous pipe. • Side wall pits allow water to pass into surrounding cells

9. Phloem • Two specialised cell types • Sieve tubes • Companion cells Phloem is the food transport tissue of the plant

10. Phloem Sieve tubes • Long, wide, living cells. • Stacked end to end from root to leaf. • End walls have Sieve Plates. • No lignin present. • Transports products of photosynthesis from leaves to the rest of the plant. • Companion Cells – control the activity of the sieve tube. Always found attached to sieve tube cell.

11. Diagram of Phloem cells