2.54 Transpiration

- In order for evaporation to occur in the stomatal pores (water goes from liquid phase to gas phase), heat is required
- As the structure of the leaf absorbs the light energy, which is absorbed from the sun gets, converted to heat
- Water taken up in the root system by osmosis then through the stem and out the petiole.
- Not all of the sunlight is absorbed by the chloroplasts, it is absorbed by other cells which then generate heat.
- Then the gas (water vapour), diffuses through the pores to the outside atmosphere down a steep diffusion gradient

2.53 Uptake of Water

- Root hairs are made of epidermal cells
- Minerals go into the plant by active transport
- Water goes into the root hair by osmosis
- The cell wall expands, therefore, there is more surface area for osmosis to occur
- The xylem transports the minerals and water up the roots and through the whole plant