What are the three layers that make up the pericarp of a fruit?

The pericarp of a fruit is composed of three distinct layers: the endocarp, mesocarp, and exocarp.

The exocarp is the outermost layer, often functioning as a protective skin that may be thin and smooth or thick and tough, depending on the type of fruit. The mesocarp lies in the middle and varies in thickness; it is the fleshy part that often provides the bulk of the fruit's volume and can be sweet or juicy, contributing significantly to the fruit's appeal. Finally, the endocarp forms the innermost layer and directly surrounds the seeds; it can be hard and stony, as seen in stone fruits like cherries, or softer in fruits such as tomatoes.

Understanding these layers is essential for studying how fruits develop, their functions in seed protection, and their roles in plant reproduction. Other provided choices refer to components not relevant to the structure of the pericarp, focusing instead on seeds or plant organs that do not relate to the fruit's outer layers.