Transport in Plants

Plants do not have a heart or a circulatory system, but they still need to transport substances from one part of the organism to another. For AQA GCSE Biology, you need to understand the two main transport processes in plants: the movement of water and minerals through the xylem (the transpiration stream) and the movement of dissolved sugars through the phloem (translocation). This lesson covers both processes in detail, including the factors affecting the rate of transpiration.

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Water Uptake by Roots

Water enters the plant through the root hair cells, which are found on the surface of young roots. Root hair cells are specialised for absorption:

Adaptation	How It Helps
Long, thin hair-like extension	Increases the surface area in contact with soil water
Thin cell wall	Reduces the distance for water to travel into the cell
Large permanent vacuole	Maintains a low water potential inside the cell (more concentrated solution), creating a steep concentration gradient

How Water Enters the Root