| Question | Answer |
| external skeleton; tough external covering that protects and supports the body of many invertebrates | exoskeleton |
| complex carbohydrate that makes up the cell wals of fungi; also found in the external skeletons of arthropods | chitin |
| structure, such as a leg or antenna; that extends from the body wall | appendage |
| one of many branching, air filled tubes that extend throughout the bodies of many terrestrial arthropods | tracheal tube |
| small opening located along the side of the body through which air enters and leaves the body of many terrestrial arthropods | spiracle |
| organ that has layers of respiratory tissue stacked like the pages of a book; used by some terrestrial arthropods for the exchange of gases | book lungs |
| saclike organ in most terrestrial arthropods that extracts wastes from the blood, adding them to feces that move through the gut | malpighian tubule |
| process in which an arthropod sheds its exoskeleton and manufactures a larger one to take its place | molting |
| region of a crustacean formed by the fusion of the head with the thorax | cephalothorax |
| body part of a crustacean that lies just behind the head and houses most of the internal organs | thorax |
| posterior part of an arthropod's body | abdomen |
| in crustaceans, the part of the exoskeleton that covers the cephalothorax; in turtles and tortoises, the dorsal part of the shell | carapace |
| mouth part adapted for biting and grinding food | mandible |
| one of the first pair of legs of decapods | cheliped |
| flipperlike appendages used by decapods for swimming | swimmeret |
| pair of mouthparts in chelicerates that contain fangs and are used to stab and paralyze prey | chelicera |
| pair of mouthparts in chelicerates that are usually modified to grab prey | pedipalp |
| organ in spiders that contains silk glands | spinneret |
| type of insect development characterized by a similar appearance through out all stages of the life cycle | incomplete metamorphosis |
| immature form that lacks functional sex organs and other adult structures | nymph |
| type of insect development in which the larvae look and act nothing like their parents and also feed in completely different ways | complete metamorphosis |
| stage of metamorphosis in which an insect changes from a larva into an adult | pupa |
| specific chemical messenger that affects the behavior or developement of other individuals of the same species | pheromone |
| group of closely related animals of the same species that work together for the benefit of the group | society |
| group of individual insects specialized to perform particular tasks or roles | castes |
| structural support located inside the body of an animal | endoskeleton |
| system of internal tubes in echinoderms that carries out essential functions such as feeding, respiration, circulation, and movement | water vascular system |
| sievelike structure through which the water vascular system of echinoderm opens to the outside | madreporite |
| suction-cuplike structure attached to radial canals of echinoderms; used to walk and to open shells | tubefoot |
