State that water is absorbed by root hair cells.
8.1 Transport in Plants
Objective
State that water is absorbed by root hair cells 🧬.
What are Root Hair Cells?
Root hair cells are tiny, hair‑like extensions of the epidermis in plant roots. They increase the surface area, making it easier for the plant to pick up water and minerals from the soil, just like a sponge soaking up water.
| Root Layer | Function |
|---|---|
| Epidermis (root hairs) | Absorb water & minerals |
| Cortex | Store food & transport |
| Endodermis | Control flow into vascular system |
| Xylem | Transport water upwards |
Analogy: Water Pipeline
Think of the plant as a city. Root hairs are like tiny water pipes that bring water from the ground into the city. The xylem is the main highway that carries this water up to the leaves, where it is used for photosynthesis.
Exam Tips
- Remember: root hair cells are the first point of contact for water absorption.
- Use the analogy of a sponge or pipeline to explain the role of root hairs.
- Draw a simple diagram of the root layers and label where water enters.
- Practice explaining why increased surface area helps absorption.
Quick Check
What is the main function of root hair cells? (Answer: Absorb water and minerals from soil)
Water molecules are represented as $H_2O$.
The process can be summarised by the equation:
$$\text{Water absorption} = \text{Surface area} \times \text{Concentration gradient}$$
Revision
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