Topic 6 - Transpiration And The Stomata Flashcards
What is transpiration?
The loss of water vapor from the leaves and stems of the plant
Transpiration is a consequence of gaseous exchange through stomata.
What role do stomata play in transpiration?
Stomata open to allow gas exchange, resulting in water evaporation
Water also evaporates at the open stomata on the leaf surfaces.
How does transpiration affect water movement in plants?
It pulls water up through the xylem, resulting in a continuous transpiration stream
This process allows more water to be taken up from the soil.
What are guard cells?
Cells that close and open stomata
They are kidney-shaped and regulate gas exchange and water loss.
Describe the structure of guard cells.
They have thin outer walls and thick inner walls
This structural difference helps them change shape to open or close stomata.
What happens to guard cells when lots of water is available?
The cells fill and change shape, opening stomata
Guard cells are also sensitive to light.
Where are more stomata found on a leaf?
On the bottom of the leaf
This location minimizes water loss by evaporation as the lower surface is shaded and cooler.
Fill in the blank: Transpiration is a consequence of _______.
[gaseous exchange]
True or False: Guard cells are only found on the top surface of the leaf.
False
More stomata are found on the bottom surface of the leaf.
