Dye Uptake and Xylem Transport in Plants

Steps:

• Plants absorb water and dissolved substances, like dye, through root hairs via osmosis and diffusion.
• The dye moves upward from roots to stem through the xylem vessels by transpiration pull.
• After 24 hours, dye accumulates in vascular tissues of both root and stem sections.
• Diagrams showing stained xylem in root and stem match the expected results.

Why A is correct:

• Option A depicts black dye in the xylem of both root and stem sections, aligning with the principle of apoplastic and symplastic pathways for solute transport in plants.

Why the others are wrong:

• B shows dye only in roots, ignoring xylem transport to stem.
• C shows dye only in stem, contradicting root absorption.
• D shows no dye anywhere, which defies absorption from dyed water.

Final answer: A