Transport of water

• What is transpiration?

  Loss of water vapor from stomata
• What causes water vapor to evaporate from stomata?

  Evaporation process
• Where are stomata mainly found on leaves?

  On the lower side of the leaf
• What are the four key conditions affecting transpiration rates?

  • Light intensity
  • Temperature
  • Humidity
  • Wind
• How does light intensity affect transpiration rates?

  Higher light intensity increases transpiration rate
• Why does temperature affect transpiration rates?

  Higher temperature increases water molecule kinetic energy
• How does humidity affect transpiration rates?

  Higher humidity decreases transpiration rate
• Why does wind affect transpiration rates?

  Wind carries away water vapor, increasing evaporation
• What is the cohesion tension theory?

  Explains water movement up plants against gravity
• What is cohesion in the context of water molecules?

  Sticking together of water molecules
• How do hydrogen bonds relate to cohesion?

  Hydrogen bonds cause water molecules to stick together
• What is the impact of cohesion on water movement in xylem?

  Creates a continuous water column in xylem
• What is adhesion in the context of water molecules?

  Water molecules sticking to xylem walls
• How does capillarity relate to adhesion?

  Adhesion helps water move up narrow xylem
• What role does root pressure play in water movement?

  Increases pressure to push water upwards
• How does transpiration create negative pressure?

  Loss of water volume lowers pressure in leaves
• What is the relationship between cohesion and water column movement?

  Cohesion allows water to move as a continuous column
• How does tension affect the xylem walls during water movement?

  Tension pulls xylem walls inward, narrowing diameter
• What are the components of the cohesion tension theory?

  • Cohesion: water molecules stick together
  • Adhesion: water molecules stick to xylem walls
  • Root pressure: pushes water upwards from roots
• What is the main outcome of transpiration?

  Loss of water vapor from stomata
• How does the diameter of the xylem affect capillarity?

  Narrower xylem increases capillarity effect
• What happens to the xylem diameter as tension increases?

  Xylem diameter narrows with increased tension