Which statement best describes a key feature of arthropods?

Which statement best describes a key feature of arthropods?

• A. Jointed appendages and a segmented body
• B. Radial symmetry
• C. Backbone present
• D. Cartilaginous skeleton

Answer: (A)

Arthropods are defined by a segmented body and jointed appendages, a combination that underpins their wide variety of forms and functions. The segmented body means the animal is built in repeated sections, which allows for specialization of different body regions and flexible growth. The jointed appendages enable precise, versatile movements and adaptations across insects, arachnids, crustaceans, and myriapods. This feature set also aligns with their external skeleton, which supports and protects the body and is shed as they grow. Radial symmetry is characteristic of other groups like jellyfish and starfish, not arthropods. A backbone is a feature of vertebrates, and a cartilaginous skeleton is typical of certain fishes. In contrast, arthropods lack internal backbones and have an external, jointed body plan.

Arthropods are defined by a segmented body and jointed appendages, a combination that underpins their wide variety of forms and functions. The segmented body means the animal is built in repeated sections, which allows for specialization of different body regions and flexible growth. The jointed appendages enable precise, versatile movements and adaptations across insects, arachnids, crustaceans, and myriapods. This feature set also aligns with their external skeleton, which supports and protects the body and is shed as they grow.

Radial symmetry is characteristic of other groups like jellyfish and starfish, not arthropods. A backbone is a feature of vertebrates, and a cartilaginous skeleton is typical of certain fishes. In contrast, arthropods lack internal backbones and have an external, jointed body plan.