Root Hair Cell
A root hair cell is a specialised plant cell that absorbs water and mineral ions from the soil 1. It is a cell of the root’s outer layer with a long, narrow extension — the root hair — pushed out between soil particles.
Adaptations for Absorption
soil particles
○ ○ ○ ┌──────────────┐
○ │ root hair │
○ ○│ cell │
└──────────────┘ long extension →
large surface area more contact with soil| Feature | Advantage |
|---|---|
| Long hair-like extension | Large surface area, so the uptake of water and mineral ions is faster |
| Thin cell wall and cell membrane | Short distance for substances to cross |
| No chloroplasts | Underground there is no light for photosynthesis |
| Many mitochondria | Release energy for active transport of ions |
Water enters by osmosis and mineral ions are taken up by active transport, which uses energy released by respiration because the ions are moved against a concentration gradient 1. Water then passes across the root cortex to the xylem and up to the leaves.
Related
- Cell - Specialised cells have specific functions.
- Cell Membrane - Route by which water and ions enter.
- Water Potential - Why soil water enters the root hair cell.
- Osmosis - Water movement that supplies the root hair cell.
- Active Transport - Process that takes in mineral ions against the gradient.
- Mitochondrion - Supplies energy for active transport.
- Nutrition - Mineral ions absorbed are used to build the plant.
- Biology - Cambridge IGCSE life-science area.
Footnotes
-
Cambridge IGCSE Biology 0610 syllabus for examination in 2026, 2027 and 2028 - Root hair cells and absorption (2.1.6b), water uptake and the pathway through the root (8.2), active transport of ions into root hairs (3.3.2). ↩ ↩2