| A | B |
|---|
| mollusks | invertebrate with a soft body; may have hard shell |
| gastropods | mollusk that glides on a foot underneath its body, such as a snail or slug. |
| bivalves | mollusk with 2 shells hinged together, such as a clam or oyster. |
| cephalopods | mollusk with distinct head and a foot divided into tentacles, such as a squid or octopus. |
| thorax | middle or chest of arthropod's body where legs are attached |
| abdomen | part of the body with many of the animal's organs in arthropods and vertebrates, |
| exoskeleton | hard outer support structure of a arthropod |
| arthropods | invertebrate with jointed appendages and segmented body, such as a spider, insect, or lobster. |
| arachnids | arthropods that have 2 main body regions, such as spiders, ticks, and scorpions. |
| crustaceans | arthropod with a hard outer "shell" and specialized appendages; such as a lobster or crab. |
| antennas | pair of appendages extending from the head of certain arthropods, used for balancing and sensing. |
| metamorphosis | process of development in which a young organism undergoes changes in appearance to become an adult. |
| nymph | stage in certain insect metamorphosis, such as that of a grasshopper, in which the organism looks like an adult but has no wings and cannot reproduce. |
| pupa | stage of metamorphosis in which an insect is often surrounded by a cocoon and many changes occur. |
| echinoderms | invertebrate with spines and tubefeet (sand dollar;sea star). |
| gestation period | time young mammals spend developing inside the womb |
| appendage | an attachment such as a leg |
| endotherm | warmblooded; keeping a stable internal temperature |
| ectotherm | coldblooded; using the environment for heat |
| bioluminescence | the ability of some living things to produce light |
| water-vascular system | used by Echinoderms for tubefeet in order to move |
| mammals | class of chordates with fur |
| vertebrates | Chordates only |
| bilateral symmetry | two sides that are similar |
| radial symmetry | many similar parts from the center |
| asymmetry | not having a definite pattern or similarity |
| endoskeleton | inner structure of support made of bone or cartilege |
