Erm... those are the pathways to the xylem, from the root hair cells. Not the pathways along/through the xylem.
(Original post by Lama88)
Xylem contains two pathways
Symplast -goes through the living parts of the cell-the cytoplasm.The cytoplasm of neighbouring cells connect through plasmodesmata.
Apoplast goes through the non-living parts of the cell-the cell wall.The walls are absorbent and water can simply diffuse through them.
Apolplast pathway gets to the endodermis cells ,its path is blocked by a waxy strip in the cell wall called the Casparian strip.As a result water goes through symplast pathway. Useful because it has to go through a cell membrane .Once past this barrier ,the water moves into the xylem vessel.
OP: I'd advise getting hold of a textbook, that should contain anything and everything that you're expected to know about them, and you can just learn that.
Notes are fallible, textbooks ought not be.
Last edited by Hearty_Beast; 16-04-2012 at 15:03.