AP BIOLOGY

Detailed explanation-1: -Sieve tubes, which are columns of sieve tube cells having perforated sievelike areas in their lateral or end walls, provide the main channels in which food substances travel throughout a vascular plant.

Detailed explanation-2: -phloem: The part of a plant that carries sugars and other products of photosynthesis from where they are made in the leaves to where they are needed.

Detailed explanation-3: -Phloem are thinner tubes than xylem. They carry the glucose made in photosynthesis. They move the glucose from the leaves to wherever it is needed in the plant’s body.

Detailed explanation-4: -The xylem distributes water and dissolved minerals upward through the plant, from the roots to the leaves. The phloem carries food downward from the leaves to the roots.

Detailed explanation-5: -Phloem are tissues that look like tubes. They transport sugars throughout the plant and supply it to tissues like roots, flowers and fruits that depend on this sugar to grow. Think of them like the veins in our body that move blood. Moving sugars from cells in the leaves to cells in the phloem is difficult for plants.