Plant tissuesSpec 4.2.3.1
In short
Plant tissues are groups of cells whose structure suits their function. Epidermal tissues cover and protect the plant, palisade mesophyll has many chloroplasts for photosynthesis, and spongy mesophyll has air spaces for gases to diffuse. Xylem transports water and mineral ions, phloem transports dissolved sugars, and meristem tissue produces new cells for growth.
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 |
Always give structure and function together: ‘many chloroplasts, so absorbs more light for photosynthesis’.
Written and checked against the AQA GCSE Biology (8461) specification · Updated October 2026