transpiration and factors affecting it

• what is transpiration caused by

  the evaporation & diffusion of water from a plant’s surfce
• where does most transpiration happen?

  the leaves
• what is transpiration rate affected by?

  • light intensity (brighter light = greater transpiration rate)
  • temperature (warmer = faster)
  • air flow (better air flow = greater transpiration)
  • humidity (drier air = faster)
• what can you use to estimate the rate of transpiration?

  a potometer
• what opens and closes the stomata?

  guard cells