Organisation: Transpiration Flashcards
What is transpiration?
Transpiration is the evaporation of water vapour from the surface of a plant.
How does transpiration work?
- Water evaporates from the leaf via the stomata.
- This creates a slight shortage of water in the leaf and so more water is drawn up from the rest of the plant to rep[lace up.
- This in turn means more water is drawn up from the roots creating s constant transpiration stream through the plant.
How does temperature affect the rate of transpiration?
Increasing the temperature increases the rate of transpiration.
How does an increases temperature increase the rate of transpiration?
Higher rate of evaporation and diffusion of water.
Therefore rate of transpiration i increased
How does humidity affect the rate of transpiration?
Increasing relative humidity decreases the rate of transpiration.
How does increases humidity decrease the rate of transpiration?
High relative humidity will reduce the water vapour concentration gradient.
The rate of diffusion will decrease and so will the rate of transpiration.
How does wind speed affect the rate of transpiration?
Increased wind speed/air movement increases the rate for transpiration.
How does increased wind speed increase the rate of transpiration?
Lowers water vapour concentration outside the leaf.
This increases the water vapour concentration gradient.
Which increases the rate of diffusion and transpiration.
How does light intensity affect the rate of transpiration?
Increasing the light intensity increases the rate of transpiration.
How does increased light intensity increase the rate of transpiration?
Increased rate of photosynthesis.
So more stomata open.
Allowing the rate of evaporation to increase, increasing the rate of transpiration.
What 4 factors can affect the rate of transpiration?
- temperature
- humidity
- wind speed
- light intensity
