The part of the plant that gets water and nutrients to the rest of the plant is the stem. It acts as the plant’s central transport route, linking the roots with leaves, flowers, and fruits.
Inside the stem are two vascular tissues. Xylem carries water and dissolved mineral nutrients upward from the roots, while phloem distributes sugars made in the leaves to areas that need energy or storage. In woody plants, the trunk is simply a large, strengthened stem.
Water rises through xylem partly because evaporation from leaves creates a pulling force called transpiration. Root pressure and the cohesion of water molecules also help maintain the continuous water column. This is why a cut flower can absorb colored water and develop tinted veins.
A common mix-up is answering “roots,” since roots absorb water and minerals from the soil. However, absorption happens in the roots; transportation throughout the plant is the stem’s defining role. Leaves also contain transport tissue, but the stem is the standard single answer for this question.