Permeability of Plant Cell Walls to Water

Steps:

• Statement 1: Cellulose forms porous cell walls that allow water molecules to diffuse through freely.
• Statement 2: Lignin impregnates walls, making them rigid and impermeable to water passage.
• Statement 3: Suberin is a hydrophobic wax that seals cell walls, blocking water movement.
• Only statements 1 and 2 are correct, matching option B.

Why B is correct:

• Cell wall permeability follows the apoplast pathway principle, where water moves through non-lignified, non-suberized walls but is barred by lignin or suberin modifications.

Why the others are wrong:

• A includes 3, but suberin prevents water passage in structures like the Casparian strip.
• C excludes 2, but lignified walls in xylem are impermeable to water diffusion.
• D excludes 1, but cellulose walls permit water via their hydrophilic matrix.

Final answer: B