Plants 9.1 Transportation in the Xylem

Question 1

What does light trigger in a stomata?

Answer 1

active transport of K+ into the guard cells. The higher solute concentration causes inward water movement by osmosis

Question 2

What causes the guard cells to become flaccid and close the stomata?

Answer 2

When transpiration rates need to be lowered, plant releases hormone, abscisic acid. this causes K+ to rapidly diffuse out of guard cell

Question 3

What models can be used to show water transport in xylem?

Answer 3

• 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

Question 4

What is hydrostatic pressure?

Answer 4

pressure in liquid