Water and mineral ions are taken up by the root hair cells.The mineral ions move across the cortex and across the endodermis into the xylem in the centre of the roots.The water travels through the cell walls and cell wall spaces (apoplast pathway) or through the cytoplasm (symplast pathway) and vacuoles from cell to cell by the plasmodesmata.When the water reaches the endodermis there is a waterproof layer of cells called the Casparian strip that has a waxy, waterproof substance called suberin in its cell walls. Water has to travel through the cytoplasm and plasmodesmata into the xylem in the centre of the root.

Movement of Water across the Roots
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Specification: AQA Biology (7401), AS-level, 3.3.4.2 Mass transport in plants. Topic: Mass Transport in Plants.
Key terms in this lesson
- vacuole
- A membrane-bound sac, permanent and large in plant cells, used for storage and to maintain turgor pressure.
- xylem
- Plant vascular tissue, made of dead, lignified tubular cells, that transports water and mineral ions from the roots to the leaves.
- root hair cell
- An epidermal cell of a root with a long extension that increases the surface area for the absorption of water and mineral ions.
More in Mass Transport in Plants
- Specialised Plant Cells
- Transpiration
- Movement of Water into the Root Hair Cells
- Movement of Water Up the Stem
- Movement of Water Across the Leaf
- Movement of Water Through the Stomata
- Translocation
- Phloem Loading
All 15 lessons in Mass Transport in Plants · All AQA AS-level Biology topics