Flashcards in Plants 9.1 Transportation in the Xylem Deck (4)
What does light trigger in a stomata?
active transport of K+ into the guard cells. The higher solute concentration causes inward water movement by osmosis
What causes the guard cells to become flaccid and close the stomata?
When transpiration rates need to be lowered, plant releases hormone, abscisic acid. this causes K+ to rapidly diffuse out of guard cell
What models can be used to show water transport in xylem?
- Potometers measures transpiration rates,
- chromotography paper (is made of cellulose so water rises up through it)
- Glass capillary tubes in water show how water adheres to glass so it rises (only does it in water)
- porous pots: show how water fills pores within pot to show adhesion, cohesion causes water to be drawn p the glass tube