Plant tissuesSpec 4.2.3.1
You need to be able to explain how the structures of plant tissues are related to their functions. Plant tissues include epidermal tissues, palisade mesophyll, spongy mesophyll, xylem and phloem, and meristem tissue.
| Tissue | Structure | Function |
|---|---|---|
| Epidermal tissues | A thin layer of cells covering the surface. In the leaf it is covered by a waxy layer | Protects the plant and reduces water loss. The leaf epidermis lets light through |
| Palisade mesophyll | Tall, tightly packed cells near the top of the leaf, containing many chloroplasts | Photosynthesis: absorbs light |
| Spongy mesophyll | Rounded cells with air spaces between them | Air spaces let gases such as carbon dioxide diffuse through the leaf. Photosynthesis also occurs here |
| Xylem | Hollow tubes strengthened by lignin | Transports water and mineral ions |
| Phloem | Tubes of elongated cells | Transports dissolved sugars |
| Meristem tissue | Found at the growing tips of shoots and roots. Cells divide and can become different types of cell | Produces new cells for growth |