Study Notes
Transpiration pull is a process that helps in the movement of water through plants from roots to leaves.
- Transpiration — the loss of water vapor from the aerial parts of a plant, mainly through the stomata. Example: Water evaporates from the surface of leaves.
- Cohesion — the attraction between water molecules that helps in the movement of water through the plant. Example: Water molecules stick together as they move up the xylem.
- Adhesion — the attraction between water molecules and the walls of the xylem vessels. Example: Water molecules cling to the sides of the xylem vessels.
- Xylem — the tissue responsible for the transport of water and nutrients from the roots to the rest of the plant. Example: Xylem vessels form a continuous tube from roots to leaves.
Exam Tips
Key Definitions to Remember
- Transpiration: the loss of water vapor from plant parts
- Cohesion: attraction between water molecules
- Adhesion: attraction between water molecules and xylem walls
- Xylem: tissue for water transport
Common Confusions
- Confusing transpiration with photosynthesis
- Mixing up cohesion and adhesion
Typical Exam Questions
- What is transpiration? The loss of water vapor from plant parts, mainly through stomata.
- How does cohesion aid in transpiration pull? It helps water molecules stick together, facilitating upward movement.
- What role does adhesion play in water transport? It helps water molecules cling to xylem walls, aiding upward movement.
What Examiners Usually Test
- Understanding of how water moves through plants
- Differences between cohesion and adhesion
- The role of xylem in water transport