Zoology

adapted adaptive radiation adult amino acids amphibians animals annelids anus appendages aquatic arthropods behavior biology birds blood body wall brain burrow called canal carbon cavity cells Chapter characteristics chemical chordates chromosomes ciliated cnidarians coelom complex contains crustaceans cuticle cycle cytoplasm digestive dorsal echinoderms eggs electron embryo energy enzymes epidermis evolution evolutionary excretory feeding female fertilization fibers Figure fishes flatworms fluid freshwater frog function gills glands glucose gonads habitats hormone humans insects intestine invertebrates kidney larva layer living lophophore lungs male mammals mantle marine membrane metabolic molecules molluscs mouth muscle nematocysts nerve cord nervous system notochord organs oxygen pair parasitic pharynx Photograph phyla phylum plasma prey primitive proboscis produce protein protozoa pseudocoel radial receptors reproduction reptiles respiratory secreted segments sensory shell species sperm sponges structure surface swimming tentacles tion tissue tube tubules usually ventral vertebrates wings worms