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adaptation a behavior or physical characteristic that allows an organism to survive or reproduce
fertilization the joining of a sperm and egg
vertebrate an animal that has a backbone
invertebrate Animals without a backbone.
Bilateral Symmetry One line that divides it into halves that are mirror edges.
Radial Symmetry Many lines of symmetry that all go through a central point.
larva An immature form of an animal that looks very different from the adult.
Cnidarian Invertebrates that have stinging cells and take food into a central body cavity.
Polyp The vase-shaped body plan.
Medusa The bowl-shaped body plan.
Parasite An organism that lives inside or on another organism.
Host The organism in or on which it lives
Scavenger Organisms that feed on dead or decaying material
Closed Circulatory System Blood moves only within a connected network of tubes called blood vessels
Mollusk Invertebrates with soft, unsegmented bodies that are often protected by a hard outer shell.
Open Circulatory System the blood is not always inside blood vessels.
Gill Organs that remove oxygen from the water.
Gastropod The largest group of mollusk.
Cephalopod An ocean-dwelling mollusk whose foot is adapted as tentacles that surround its mouth.
Bivalve A second group of mollusks, that include oysters, clams, scallop, and mussels.
Herbivore Animals that only eat plants.
Carnivore Animals that only eat other animals.
Omnivore Animals that eat both plants and animals.
Radula A flexible ribbon of tiny teeth, to obtain food
Arthrodpod A member of the arthropod phylum.
Exoskeleton Outer skeleton
Molting The process of shedding an outgrown exoskeleton.
Crustacean An arthropod that has two or three body sections, five or more pairs of legs and two pairs of antennae.
Complete Metamorphosis A type of metamorphosis characterized by four dramatically different stages.
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.
Arachnid An arthropod with two body sections, four pairs of legs, and no antennae.
Insect Arthropods with three body sections, six legs, one pair of antennae, and usually one or two pairs of wings.
Thorax The section to which wings and legs are attached.
Pupa The third stage of complete metamorphosis, in which an insect changes from a larva to an adult.
Nymph An egg hatches into this stage.
Echinoderm A member of the phylum echinodermata.
Endoskeleton An internal skeleton that the skin of most echinoderms is stretched over.
Water Vascular System The internal system of fluid-filled tubes in echinoderms.
Created by: christakis