| A | B |
|---|
| exoskeleton | a tough external covering |
| chitin | protein and carbohydrates |
| appendage | structures such as legs and antennae that extend from the body wall |
| tracheal tube | network of breathing tubes |
| spiracle | small openings on the side of the body |
| book lung | organs that have layers of respiratory tissue |
| malpighian tubule | saclike organs that extract wastes from the blood and then add them to feces |
| molting | an arthropod sheds its entire exoskeleton |
| cephalothorax | fusion with the head and thorax |
| thorax | body part of a crustacean that lies just behind the head and houses most of the internal organs |
| abdomen | the posterior part of the body |
| carapace | part of the exoskeleton that covers the cephalothorax |
| mandible | mouthpart adapted for biting and grinding food |
| cheliped | first pair of legs |
| swimmeret | flipperlike appendages used for swimming |
| chelicera | fangs that are used to stab and paralyze prey |
| pedipalp | fangs modifed to grab prey |
| spinneret | organs that contain silk glands |
| incomplete metamorphosis | undergo gradual change from nymphs |
| nymph | immature forms that lack sexual organs |
| complete metamorphasis | undergo dramatic change int he body |
| pupa | final molt |
| pheromone | chemical signals |
| society | group of closely related animals of the same species |
| caste | groups of individuals |
| endoskeleton | structural support located inside the body of an animal |
| water vascular system | system of internal tubes |
| madreporite | sieve like structure through which the water vascular system of an echinoderm opens to the outside |
| tubefoot | structure that operate much like suction cup |
