Answer: upward transport.
- A upward transport
- B food digestion
- C waste excretion
- D food storage
Correct answer: A. upward transport
Explanation: The transpiration stream carries absorbed minerals up the plant.
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.