Plant Structure

Function of Root Hair Cells
- Adapted for efficient uptake of water and mineral ions.
- Water is absorbed via osmosis; minerals via active transport.
Structure
- Single-celled extensions of epidermis cells in the root.
- Grow between soil particles, facilitating absorption.
Surface Area
- Root hairs significantly increase surface area-to-volume ratio, enhancing absorption rate of minerals.
Water Potential
- High proportion of dissolved minerals and sugars creates low water potential in root hair cells, causing water to enter via osmosis.
Diagram
- Illustration of a root hair cell showing adaptations for uptake.

Function
- Transport tissue for water and dissolved minerals from roots to leaves.
Structure and Adaptations
- Cells lose top and bottom walls, forming continuous hollow tubes.
- Cells are dead, lack organelles and cytoplasm, allowing free movement of water.
- Outer walls are thickened with lignin, providing structural support.

Function
- Transport dissolved sugars (e.g., sucrose) and amino acids.
Structure and Adaptations
- Composed of living cells, aided by companion cells.
- Formed tubes retain some subcellular structures unlike xylem.
Cell Joining
- Cells joined end-to-end with holes (sieve plates) allowing easy flow of sugars and amino acids.
- Few subcellular structures enhance material flow.

Be prepared to interpret unfamiliar cell structures by examining their shapes and subcellular components.
Consider features like surface area, ribosome quantity for protein synthesis, and mitochondria for energy transfer.