Answer: osmosis.
- A osmosis
- B only diffusion
- C active transport
- D respiration
Correct answer: A. osmosis
Explanation: Osmosis is the diffusion of water across a semipermeable membrane.
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.