Zusammenfassung der Ressource
B4 Transpiration
- What is transpiration? (this is from your EOY exam!)
- Stomata
- Why are stomata
necessary in a leaf?
- How are stomata
opened and
closed?
- By what process is water
lost through the
stomata?
- The number of stomata per mm2
on a leaf were counted to be 250,
280, 265, 245, 270, 255 and 290.
Calculate the mean number of
stomata to 3 significant figures.
- Investigating the rate of
transpiration
- What is the function of
the reservoir?
- How do you measure
the rate of
transpiration using a
potometer?
- Factors that affect transpiration
- If temperature is
increased, how does this
affect the rate of
transpiration?
- Explain why?
Think about
the rate of
evaporation!
- If humidity is increased, how
does this affect the rate of
transpiration?
- Explain why? Think
about the
concentration gradient
of water molcules
inside and outside of
the leaf
- If light intensity is increased,
how does this affect the rate
of transpiration?
- Explain why? Think
about the rate of
photosynthesis!
- If wind speed is increased, how
does this affect the rate of
transpiration?
- Explain why? Think about the rate of evaporation
and the conctrnation gradient of water in and out
of the leaf if water vapour is blown away quickly!
- Minimising water loss
- How does a waxy layer on the top
of the leaf reduce water loss?
- How does having most stomata on the underside of the
leaf minimise water loss?