Topic 2 Plants: Movement of Water

Question 1

• Transpiration, the driving force, causes water to evaporate from the stomata and leads to a transpirational pull
• This cohesive force (between similar substances, e.g. water molecules) pulls the water column apart

Answer 1

1. Cohesion-tension theory

Question 2

• An adhesive force (between dissimilar substances) due to attraction between water and xylem vessels that causes water to climb upwards

Answer 2

2. Capillary Action

Question 3

• Builds up in roots to produce an osmotic gradient which drives water from soil into roots

Answer 3

3. Root Pressure