Final answer:
The mantle and mantle cavity are present in mollusks. The mantle is a specialized tissue that encloses the visceral organs and secretes shells. The mantle cavity is a space between the mantle and the body that houses respiratory structures.
Step-by-step explanation:
The mantle and mantle cavity are present in the class Mollusks.
- The mantle is a specialized epidermal tissue in mollusks that encloses the visceral organs and secretes shells in some species.
- The mantle cavity is a space between the mantle and the body that houses the gills or other respiratory structures.
The presence of a mantle and mantle cavity is a defining characteristic of the class Mollusks, which includes snails, clams, and squid, among others.