| A | B |
|---|
| Invertebrates | animals that lack a backbone |
| Vertebrates | animals that have a backbone |
| Spherical symmetry | identical halves from a cut through the center |
| radial symmetry | any longitudinal cut creates identical halves |
| Bilateral symmetry | longitudinal cut creates a right and left side |
| Epidermis | outer layer of cells designed to provide protection |
| Mesenchyme | jelly-like substance that separates the epidermis from the inner layers |
| Collar cells | Flagelated cells that pump water into a sponge |
| Amebocytes | cells in a sponge that preform digestion and transport |
| Gemmule | cluster of cells encasesd in a hard, spicule-reinforced shell |
| Polyp | A sessile, tubular cnidarian with a mouth and tenticles at one end and a basal disk at the other |
| Medusa | free swimming cnidarian with a bell shaped body and tentacles |
| Edithelium | animal tissue cwith one or more layers of cells that have only one free surface |
| Mesoglea | jelly like sustance that separates the epithelial cells in a cnidarian |
| Nematocysts | small capsules that contain a toxin which is injected into prey |
| Testes | organ that produces sperm |
| Ovaries | organ that produces eggs |
| Anterior end | end that contains the head |
| Posterior end | end that contains the tail |
| Circulatory system | system to transport food and other substances through the body |
| Nervous system | sensitive cells that respond to stimuli such as sound and touch |
| ganglia | masses of nerve cell bodies |
| Hermaphroditic | possessing both male and female organs |
| Regeneration | ability to regrow a missing part |
| Mantle | sheath of tissue to enclose vital organs of a molusk |
| Shell | tough multilayered structure secreted by the mantle |
| Visceral hump | hump that contains the molusks heart, digestion, and excretory organs |
| Foot | muscular organ for locomotion |
| Radula | organ covered with teeth that molusks use to scrape foot into their mouths |
| Univalve | organism with a single shell |
| Bivalve | organism with two shells |
