1. How are Big Trees able to get water to the top??

2. Transpiration Plants continually lose water to the air. This is called transpiration.

3. Transpiration Stages in transpiration 1) Water is constantly lost from the leaves- this occurs due to evaporation due to heat + water loss from the stomata

4. Transpiration Stages in transpiration 2) This produces a concentration gradient: There is more water in the roots/ at the base of the plant that in the leaves. Water moves via osmosis from a high concentration in the roots to a lower one in the leaves.

5. Transpiration Stages in transpiration 3) As water moves from the roots to the leaves more water is drawn up from the soil into the root hair cells. This occurs because the concentration of water in the soil is larger than in the roots = water moves via osmosis in to the root hair cells.

6. The guard cells control the size of the stomata, so can regulate the amount of water lost by transpiration. If plants are losing water faster than they are gaining it, the stomata close. Without this happening, the plants will wilt – and may die.