Transpiration Flashcards
1
Q
Transpiration stream
A
Flow of water from roots to leaves
2
Q
Root pressure
A
Action of endodermis
Active transport of mineral ions into xylem
Water osmosis
3
Q
Transpiration pull
A
Cohesion-tension theory
Water (vapour) lost at top of column, pulled up as chain
Creates transpiration stream
Pull from above creates tension in column
4
Q
Capillary action
A
Adhesion of water molecules to sides of xylem vessel as they’re narrow
5
Q
Casparian strip
A
Blocks apoplast pathway between cortex and xylem
Ensures water and NO3- through membrane
Membrane transporter proteins
Nitrate ions lower water potential in xylem, osmosis
Water can’t pass back into cortex as apoplast pathway of endodermal cells is blocked
6
Q
Transpiration. Define
A
The loss of water vapour from the leaf
