Label and draw in Symplast/Apoplast Pathway

Root Hair Cells Endodermis Xylem Cortex Phloem

From Soil to root Apoplast Pathway Symplast Pathway Endodermis Soil Root hair cell Cortex Xylem Casparian Strip

Osmosis Osmosis Osmosis High – Low Water Potential Minerals actively transported into root hair cell Low Water Potential Minerals actively transported into xylem Low Water Potential

10 minutes

Movement of Water Up Stem: Root Pressure Endodermis moves minerals into xylem (active transport) Creates water potential gradient Water is forced into the xylem, and pushed up Accounts for some of the reason why water moves up xylem – but not all of it

Movement of water up a stem: Capillary Action Forces that hold water together also attract water to the sides of the xylem This is Adhesion Xylem vessels are narrow, this attraction can pull water up sides of vessel

Movement of water up a stem: Transpiration pull Water is lost from leaves - this water must be replaced Water molecules attracted to each other – Cohesion Hold molecules together in a long column Column is pulled up where water is lost at the top Pull = tension, which is why xylem is reinforced Cohesion-Tension theory

Cuticle Upper Epidermis Mesophyll cells xylem/phloem space Lower Epidermis Guard cell Stoma

Water enters leaf from xylem Water enters cell walls and cytoplasm of mesophyll cells Water vapour in space If lower water potential in atmosphere – water lost out of stomata Transpiration

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