General Zoology

abdomen acid adult amphibians animals annelids antennae anus appendages aquatic arteries arthropods birds blood vessels body wall bones brain burrows cavity cells Chap chromosomes ciliated CLASS cloaca coelom color contains crustaceans cuticle digestive tract dorsal duct eggs embryo epidermis esophagus excretory external eyes feed feet female fibers fins fishes fluid fossil fresh-water frog gametes gastrula germ layers gill slits glands gonads head heart hind inches insects intestine invertebrates jaws kidney larvae lateral layers legs limbs liver living lophophore lungs male mammals marine membrane mollusks mouth muscles nematocysts nephridia nephridium nerve cord nervous system notochord Order organs ovary oviduct oxygen pairs parasitic pharynx PHYLUM plants posterior produce protozoans reproductive reptiles respiration secretion segmental sensory shell skeleton skin slender snakes somites species sperm sponges stomach structure SUBORDER surface tail teeth tentacles tion tissues tube usually veins ventral vertebrates wings worms