Which of the following is an example of an arthropod?

Arthropods are a diverse group of invertebrate animals characterized by their exoskeleton, segmented bodies, and jointed appendages. Spiders are a prime example of arthropods; they belong to the class Arachnida, which is part of the larger phylum Arthropoda. This group includes other familiar creatures such as insects, crustaceans, and similar animals.

Spiders possess the distinct anatomical features typical of arthropods, including eight legs and a body divided into two segments: the cephalothorax and the abdomen. Their exoskeleton protects their bodies, and they play significant roles in various ecosystems, often as predators.

The other organisms listed do not fit the definition of arthropods. Frogs are amphibians with smooth skin and a life cycle that includes both aquatic larvae and terrestrial adults. Worms, typically referring to annelids, have segmented bodies but lack an exoskeleton. Sharks, belonging to the class Chondrichthyes, are cartilaginous fish and are not related to arthropods. Understanding these distinctions helps clarify why the spider is the correct representation of an arthropod.