Which characteristic is common to fruits?

The characteristic that is common to fruits is that they contain seeds. Fruits are the mature ovary of flowering plants, usually developed from the fertilization of flowers, and one of their key roles in plant reproduction is to protect and facilitate the dispersal of seeds. This means that seeds are an integral part of the definition and structure of what a fruit is.

Fruits can come from various parts of the plant and can vary greatly in terms of size, shape, and taste, but the presence of seeds is a fundamental aspect that distinguishes them from other plant parts. Other options suggest characteristics that do not universally apply to fruits: fruits are often eaten raw, they can grow above or below ground depending on the type, and while many fruits do contain nutrients, they are not specifically characterized by high protein content.