Which of the following is an example of Mollusca?

• A. Clams
• B. Spiders
• C. Crabs
• D. Jellyfish

Answer: (A)

Mollusca are a diverse group of invertebrates that typically have a mantle, a visceral mass, and often a calcium carbonate shell. Clams are mollusks known as bivalves, meaning their bodies are enclosed by two hinged shells. They possess a muscular foot used for digging, and a mantle that secretes the shell. This combination of features aligns with the defining traits of Mollusca.

Spiders are arthropods with segmented bodies, eight legs, and an external skeleton. Crabs are crustaceans, also arthropods, with jointed limbs and a hard exoskeleton. Jellyfish are cnidarians, simple aquatic animals with radial symmetry and stinging cells, lacking a shell and the molluscan body plan. So clams exemplify Mollusca.