The xylem vessels of a plant carry:

• A. Food down from the leaves
• B. Carbon dioxide into the leaves
• C. Chlorophyll to assist in photosynthesis
• D. Water up from the roots

Answer: (D)

Water and dissolved minerals are carried upward from the roots through the xylem. This movement is driven by transpiration from the leaves, which creates a pull that pulls water up the plant in a continuous column. The xylem is made of lignified, hollow, dead cells that withstand tension, and water’s cohesion and adhesion help keep the column intact as it moves upward. Chlorophyll stays in the leaf cells, and sugars produced by photosynthesis travel through the phloem to other parts of the plant, not the xylem. CO2 is taken in through stomata and used in photosynthesis inside leaf cells, not transported up the plant via xylem. So the xylem’s role is to move water upward from the roots.