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
Main limitation of root pressure
Main limitation of root pressure
Cannot explain water transport in very tall trees
Guttation
Guttation
Water droplets on leaf edges from root pressure
Cohesion in water transport
Cohesion in water transport
Water molecules stick together via hydrogen bonding
Adhesion in water transport
Adhesion in water transport
Water molecules stick to xylem vessel walls
Cohesion-tension theory discoverers
Cohesion-tension theory discoverers
Henry Dixon and John Joly, 1894
Role of transpiration in water movement
Role of transpiration in water movement
Creates pulling force on water column from top
Max height cohesion-tension explains
Max height cohesion-tension explains
150 metres tall
Daytime effect on stem width
Daytime effect on stem width
Stems narrow due to increased transpiration tension
Stomata function
Stomata function
Tiny pores controlling gas exchange and water loss
Turgid guard cells effect
Turgid guard cells effect
Buckle outwards, opening the stoma
Flaccid guard cells effect
Flaccid guard cells effect
Shrink and close the stoma
High effect on stomata
High effect on stomata
Stomata close
Low effect on stomata
Low effect on stomata
Stomata open