Final Answer:
C) Arthropods have exoskeletons
Step-by-step explanation:
C) Arthropods, represented by insects, arachnids, crustaceans, and myriapods, possess exoskeletons. An exoskeleton is a rigid external covering that provides structural support and protection to the organism. In arthropods, this exoskeleton is primarily composed of chitin, a tough polysaccharide. This unique feature distinguishes them from the other options listed.
Firstly, Annelids, such as earthworms, do not have exoskeletons but rather possess hydrostatic skeletons, utilizing fluid pressure for support. Mollusks, represented by creatures like snails and clams, have a soft, uncalcified body covering, known as the mantle, and typically lack an exoskeleton. Echinoderms, like starfish and sea urchins, exhibit an endoskeleton composed of ossicles beneath their skin, ruling out the presence of an exoskeleton.
Secondly, vertebrates, including mammals, reptiles, and birds, have endoskeletons made of bone or cartilage. This internal skeletal structure provides support and protects internal organs but differs fundamentally from the external exoskeleton of arthropods.
In summary, the presence of an exoskeleton is a characteristic feature of arthropods, making option C the correct answer in this context. The diversity of skeletal structures among different animal phyla reflects the fascinating adaptations that have evolved in response to various environmental challenges.