| A | B |
|---|
| MOLLUSK | An invertebrate with a soft, unsegmented body; most are protected by a hard outer shell |
| KIDNEY | A major organ of the excretory system; eliminates urea, excess water, and other waste materials form the body |
| GILL | An organisms breathing organ that removes oxygen from water |
| RADULA | A flexible ribbon of tiny teeth in mollusks |
| GASTROPOD | A mollusk with a single shell or no shell |
| BIVALVE | A mollusk that has two shells held together by hinges and strong muscle |
| CEPHALOPOD | A mollusk with feet adapted to form tentacles around its mouth |
| ARTHROPOD | An invertebrate that has an external skeleton, a segmented body, and jointed attachments called appendages |
| EXOSKELETON | An outer skeleton |
| CHITIN | The tough, flexible material from which arthropod exoskeletons are made |
| MOLTING | The process of shedding an outgrown exoskeleton |
| ANTENNA | An appendage on the head of some animals that contains sense organs |
| CRUSTACEAN | An arthropod that has two or three body sections, five or more pairs of legs, two pairs of antenna, and usually three pairs of appendages for chewing |
| METAMORPHOSIS | A process in which an animal’s body undergoes dramatic changes in form during its lifecycle |
| ARACHNID | An arthropod with only two body sections |
| ABDOMEN | The hind section of an arachnid’s body that contains its reproductive organs and part of its digestive tract |
| ABDOMEN | The hind section of an insect’s body |
| INSECT | An arthropod with three body sections, six legs, one pair of antennae, and usually one or two pairs of wings |
| THORAX | An insect’s mid-section, to which its wings and legs are attached |
| COMPLETE METAMOPHOSIS | A type of metamorphosis characterized by four dramatically different stages; egg, larva, pupa and adult |
| PUPA | The second stage of complete metamorphosis, in which an insect is enclosed in a protective covering and gradually changes from a larva to an adult |
| GRADUAL METAMORPHOSIS | A type of metamorphosis in which an egg hatches into a nymph that resembles an adult, and which has no distinctly different larval stage |
| NYMPH | A stage of gradual metamorphosis that usually resembles the adult insect |
| CAMOUFLAGE | Protective coloration; a common animal defense |
| PHEROMONE | A chemical released by one animal that affects the behavior of another animal of the same species |
| BIOLUMINESCENCE | The production of light by a living organism |
| ECHINODERM | A radially symmetrical invertebrate that lives on the ocean floor and has a spiny internal skeleton |
| ENDOSKELETON | An internal skeleton |
| WATER VASCULAR SYSTEM | A system of fluid - filled tubes in an echinoderm’s body |
