Upward Movement of Water in Plants (Leaving Cert Biology): Flashcards
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Practise the cards
14 cards from this deck
Root pressure
Root pressure
Pressure from osmosis pushing water up through xylem
Water transport vessels in plants
Water transport vessels in plants
Xylem
Guttation
Guttation
Water droplets on leaf edges from root pressure
Root pressure limitation
Root pressure limitation
Too weak to explain water transport in very tall trees
Cohesion-tension theory originators
Cohesion-tension theory originators
Henry Dixon and John Joly (1894)
Cohesion
Cohesion
Water molecules sticking to each other
Adhesion
Adhesion
Water molecules sticking to xylem walls
Stomata
Stomata
Tiny pores on leaves controlling gas exchange and water loss
Guard cells
Guard cells
Kidney-shaped cells surrounding and controlling stomata
Turgid guard cells effect
Turgid guard cells effect
Guard cells buckle outwards, opening the stoma
Flaccid guard cells effect
Flaccid guard cells effect
Guard cells shrink, closing the stoma
High effect on stomata
High effect on stomata
Stomata close
Low effect on stomata
Low effect on stomata
Stomata open
Daytime stem width change
Daytime stem width change
Stems narrow due to increased transpiration tension in xylem