Zusammenfassung der Ressource
Transpiration
- Factors Afecting:
- Humidity
- Transpiration is slower because the leaf is already surrounded by moist air, and so diffusion out of
the leaf slows down
- WInd
- Transpiration is faster because the wind causes the water vapour to move quickly, speeding up diffusion
- Temperature
- Transpiration is higher in high temperatures, because evaporation and diffusion occurs quicker
- Light
- Higher light intensities causes higher amounts of transpiration, because the stomata opens wider to allow more CO2 into the leaf for photsynthesis
- The movement of water up the Xylem
- Water on the spongy mesophyll and palisade cells evaporate and diffuse out of the leaf
- More water is drawn out the Xylem to replace what's lost
- When the stomata open to allow the exchange of CO2 and O2 between the air inside and outside the leaf, water vapour is also lost through diffusion. Loss of water through leaf and stem is called Transpiration
- Stomata open and close to control amount of H2O lost by plant.
- DAY: Plant needs CO2 for photosynthesis
- NIGHT: No O2 is being produced by photosynthesis and so needs O2 for respiration
- At least some stomata need to stay open all the time