The structure that carries sugar from a plant's leaves to the rest of the plant is called the phloem.

Here's how it works:

* Photosynthesis: Sugar (glucose) is produced in the leaves through photosynthesis.

* Phloem: The phloem is a network of living cells that forms a vascular tissue in plants. It's made up of sieve tubes and companion cells.

* Transport: Sugar is transported through the phloem from the leaves to other parts of the plant, such as the roots, stem, and fruits, where it's used for growth, energy, and storage.

Think of it like a pipeline for sugar!