ambulacral - one of the radial areas bearing tube feet

atrophy - degeneration

bilateral symmetry - a body plan in which an organism's left and right sides are exact mirror images of one another

chloroplast - the organelle in plants where chlorophyll is located for photosynthesis

cilia - very small hair-like organelles used for locomotion

coelom - a body cavity created by division of the mesoderm

diffusion - the passive movement of atoms or molecules by means of moving from high concentration to low concentration

dioecious - a species having separate male and female individuals

dorsal - upper side of the body

endoskeleton - an internal supporting skeleton or framework

gametes - mature sexual reproductive cells

heterotrophic - an organism that cannot make its own food

hydrostatic skeleton - a system that provides support and locomotion by means of utilizing pressure from a fluid-filled cavity and surrounding muscles

madreporite - a plate that allows for water to enter the water vascular system

monophyletic - having evolved from one common ancestor

motile - possessing the ability to move

nucleus - an organelle responsible for housing DNA

olfactory sense - senses pertaining to smell

organelle - a specialized part of a cell that has a specific function (a cell organ)

pedicellariae - very small, pincher-like structures used for cleaning and sometimes capturing very small prey

pentaradial symmetry - a form of radial symmetry that can only be broken into planes of multiples of five

polyphyletic - having evolved from more than one common ancestor

triploblastic - having three germ layers

ventral - under side of the body

Send questions or comments to richards.mic2@students.uwlax.edu