What defines an aggregate fruit?

An aggregate fruit is characterized by its development from multiple ovaries of a single flower. This means that during the flowering process, the flower produces several pistils (the reproductive part of the flower that contains the ovary) which then each develop into a small fruit, leading to a composite structure that we recognize as an aggregate fruit. Examples of aggregate fruits include raspberries and blackberries, where each small drupelet comes from a separate ovary of the same flower.

The other options don’t accurately define aggregate fruits. For example, a fruit forming from many clustered flowers refers more to multiple flowers contributing to the development of a single fruit structure, which characterizes a different category of fruit known as a multiple fruit. Meanwhile, having multiple mature seeds doesn’t distinguish aggregate fruits specifically, as many fruit types can have numerous seeds. Finally, the development of a fruit from multiple floral structures does not directly relate to aggregate fruits, as aggregate fruits arise specifically from multiple ovaries within a single flower.