Answer: xylem.
- A xylem
- B phloem
- C epidermis
- D cortex
Correct answer: A. xylem
Explanation: Xylem conducts water and dissolved minerals from roots to leaves.
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.