NOCTI Plant Science Practice Test

Water moving from roots to leaves is carried through the xylem, a vascular tissue specialized for water transport. Xylem vessels and tracheids form continuous tubes that travel upward, driven by transpiration pull and aided by cohesion and adhesion. This setup moves water and dissolved minerals efficiently to all parts of the plant.

Phloem, in contrast, transports sugars and other organic nutrients produced by photosynthesis, not water. Cambium is a growth tissue that generates new xylem and phloem during secondary growth, and sclerenchyma provides structural support with thick, hard cell walls.