Compare apoplast and symplast pathways for water movement

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The apoplast pathway and symplast pathway are the two routes water and dissolved minerals can take to move from the root hairs, across the root's cortex, and into the central vascular cylinder (where the xylem is).Here is a direct comparison:FeatureApoplast PathwaySymplast PathwayPath of MovementThrough the non-living parts of the root: the interconnected cell walls and the empty spaces *between* cells.Through the living parts of the root: from the cytoplasm of one cell directly into the cytoplasm of the next.Cell ConnectionsDoes not cross any cell membranes (until the end).Crosses from cell to cell via tiny channels called plasmodesmata.Speed of MovementFast. This path has low resistance, like water soaking into a paper towel.Slower. The movement is limited by the resistance of the cytoplasm.Metabolic ControlNo metabolic control by the plant.Yes, the plant has metabolic control as the water is inside its living cells.The "Checkpoint"This pathway is blocked at the inner layer (endodermis) by the waxy Casparian strip.This pathway can cross the Casparian strip because it is already inside the cell.Key Takeaway: All water, regardless of its path, is forced to enter the symplast pathway at the endodermis (the "checkpoint") because of the waxy Casparian strip. This blockage of the apoplast path forces all water and minerals to cross a living cell membrane, allowing the plant to filter out and reject any unwanted or toxic substances before they can enter the xylem.

Compare apoplast and symplast pathways for water movement

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Feature	Apoplast Pathway	Symplast Pathway
Path of Movement	Through the non-living parts of the root: the interconnected cell walls and the empty spaces between cells.	Through the living parts of the root: from the cytoplasm of one cell directly into the cytoplasm of the next.
Cell Connections	Does not cross any cell membranes (until the end).	Crosses from cell to cell via tiny channels called plasmodesmata.
Speed of Movement	Fast. This path has low resistance, like water soaking into a paper towel.	Slower. The movement is limited by the resistance of the cytoplasm.
Metabolic Control	No metabolic control by the plant.	Yes, the plant has metabolic control as the water is inside its living cells.
The "Checkpoint"	This pathway is blocked at the inner layer (endodermis) by the waxy Casparian strip.	This pathway can cross the Casparian strip because it is already inside the cell.