Answer: Cell walls and intercellular spaces (no membranes crossed).
- A Cell membranes and cytoplasm via osmotic gradients between cells
- B Cell walls and intercellular spaces (no membranes crossed)
- C Central vacuoles of cortical cells linked by tonoplast continuity
- D Plasmodesmata connecting the cytoplasm of adjacent cortical cells
Correct answer: B. Cell walls and intercellular spaces (no membranes crossed)
Explanation: Apoplast pathway: water moves through cell walls and intercellular spaces. Blocked at Casparian strip in endodermis, forcing water through symplast.
Water can travel through cell walls (apoplast) or cell-to-cell through the cytoplasm (symplast) - but the Casparian strip at the endodermis blocks the apoplast route entirely, forcing everything through a selectively permeable membrane (symplast) before it can enter the xylem.
Concept context
Water and mineral absorption, the ascent of sap, transpiration, and phloem transport via the pressure flow hypothesis.