Water uptake
Drinking through roots
- Water and mineral ions enter a plant through root hair cells.
- A root has a huge number of root hairs.
- This gives a very large surface area, speeding up uptake.
Practice
Water enters the plant mainly through:
Root hair cells take up water and mineral ions; their huge number gives a large surface area.
Practice
Why do root hairs speed up water uptake?
Millions of root hairs give a large surface area, so water and ions are taken up faster.
The water pathway
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Water travels from the soil to the leaf along this route:
root hair cell → root cortex → xylem → mesophyll cells in the leaf
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You can show it by standing a white flower in water with a coloured stain — the stain rises up the xylem and colours the veins.
Practice
Put the water pathway in order, from soil to leaf.
Water goes root hair → cortex → xylem → mesophyll in the leaf.
You've got it
Key idea
- water enters through root hair cells; many root hairs = large surface area
- pathway: root hair → cortex → xylem → mesophyll
- a coloured stain rising up the veins reveals the xylem pathway