Which feature is a correct description of mollusks?

Which feature is a correct description of mollusks?

• A. Chitinous exoskeleton
• B. Segmentation with jointed limbs
• C. Radial symmetry
• D. Mantle secreting shell

Answer: (D)

A defining trait to consider is the mantle, a specialized tissue that often builds and maintains a shell by secreting calcium carbonate. This shell-secreting mantle is a hallmark feature seen in many mollusks such as snails and clams, making it the best description of mollusks among the options. The other features point to other groups: a hard chitinous exoskeleton and segmentation with jointed limbs are typical of arthropods; radial symmetry is characteristic of cnidarians and echinoderms. While some mollusks (like octopuses) may lack an external shell, the mantle’s secretion of a shell remains the classic molluscan trait.

A defining trait to consider is the mantle, a specialized tissue that often builds and maintains a shell by secreting calcium carbonate. This shell-secreting mantle is a hallmark feature seen in many mollusks such as snails and clams, making it the best description of mollusks among the options. The other features point to other groups: a hard chitinous exoskeleton and segmentation with jointed limbs are typical of arthropods; radial symmetry is characteristic of cnidarians and echinoderms. While some mollusks (like octopuses) may lack an external shell, the mantle’s secretion of a shell remains the classic molluscan trait.