Biology STAAR Practice Test 2026 - Free State of Texas Assessments of Academic Readiness Practice Questions and Study Guide

The statement that accurately describes arthropods is that they possess jointed appendages and an exoskeleton. Arthropods, which include insects, arachnids, crustaceans, and myriapods, are characterized by their segmented bodies, jointed limbs, and a hard outer covering known as an exoskeleton made of chitin. This exoskeleton provides structural support and protection, allowing for mobility and adaptation to various environments.

In addition to their exoskeleton, arthropods have jointed appendages, which may function as legs, antennae, or mouthparts, providing them with a wide range of movement and the ability to interact effectively with their environment. This combination of characteristics is fundamental to the classification of arthropods and distinguishes them from other animal groups.

The other statements do not accurately capture the defining traits of arthropods, as they can inhabit diverse environments, including terrestrial, freshwater, and marine ecosystems, and they do not solely rely on gills for respiration; many arthropods, such as insects, breathe through tracheae.