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• How water moves across roots

  1. Water moves from soil into root hair cells

  2. Water moves across cells via apoplast pathway (through cell wall) and symplast pathway (through cytoplasm and plasmodesmata)

  3. Water reaches endodermis and encounters Casparian strip (made of suberin)

  4. Water forced to move through symplast pathway across endodermis

  5. Mineral ions actively transported into xylem, decreasing water potential and causing water to move into xylem by osmosis

  6. Root pressure pushes water up xylem to rest of plant
• Casparian strip


  • Embedded in cell wall of endodermis cells
  • Made of waxy substance suberin
  • Blocks water movement through apoplast pathway, forcing water through symplast pathway
• Apoplast pathway is the preferred pathway for water movement across cells
• Symplast pathway involves water moving through cytoplasm and crossing plasma membranes via osmosis
• Plasma membrane is selectively permeable, allowing it to filter out toxins
• Mineral ions are actively transported into xylem, decreasing water potential and causing water to move into xylem by osmosis
• Root pressure pushes water up xylem to rest of plant
• Transpiration also contributes to water movement up the plant
• what are the two ways water moves across root hair cells

  apoplast pathway and symplast pathway
• how does water move through the apoplast pathway

  through cell walls by tension
• and how does water move through the symplast pathway

  through cytoplasm by diffusion and plasmodesmata by osmosis