- Water molecules are attracted to each other by cohesion - creating a continuous column of water up the plant
- Water moves through the xylem vessels in a continuous transpiration stream from roots to leaves via the stem
- Transpiration produces a tension or ‘pull’ on the water in the xylem vessels by the leaves
- As water molecules are held together by cohesive forces (each individual molecule ‘pulls’ on the one below it), so water is pulled up through the plant
- If the rate of transpiration from the leaves increases, water molecules are pulled up the xylem vessels quicker
The generation of the transpiration stream