Which tissue carries water upward from the roots to every part of the plant?

Which tissue carries water upward from the roots to every part of the plant?

• A. Phloem
• B. Cambium Layer
• C. Xylem
• D. Heartwood

Answer: (C)

Water transport upward in plants occurs mainly through xylem, a tissue made of hollow, dead cells with thick, lignified walls. These sturdy conduits form continuous tubes from roots to leaves, letting water and minerals move upward as the plant transpires. The driving force is a combination of transpiration pulling on water columns (cohesion-tension) and some root pressure that can push water up from the roots. Xylem vessels and, to a lesser extent, tracheids, are specialized for this single-direction flow, which is why they’re ideal for moving water from roots to every part of the plant. Phloem carries dissolved sugars and other nutrients, and it can transport in multiple directions depending on source and sink demands, not just upward. The cambium layer is a growth tissue responsible for producing new xylem and phloem during secondary growth, not a transport tissue itself. Heartwood is older, nonconductive wood that no longer transports water.

Water transport upward in plants occurs mainly through xylem, a tissue made of hollow, dead cells with thick, lignified walls. These sturdy conduits form continuous tubes from roots to leaves, letting water and minerals move upward as the plant transpires. The driving force is a combination of transpiration pulling on water columns (cohesion-tension) and some root pressure that can push water up from the roots. Xylem vessels and, to a lesser extent, tracheids, are specialized for this single-direction flow, which is why they’re ideal for moving water from roots to every part of the plant.

Phloem carries dissolved sugars and other nutrients, and it can transport in multiple directions depending on source and sink demands, not just upward. The cambium layer is a growth tissue responsible for producing new xylem and phloem during secondary growth, not a transport tissue itself. Heartwood is older, nonconductive wood that no longer transports water.