| A | B |
|---|
| asymmetrical | without symmetry |
| radial symmetry | symmetry repeats around a circle like spokes on a wheel |
| bilateral symmetry | a line down the middle separates the organism into two identical halves |
| tissue | a group of identical cells working together |
| cephalization | development of a brain and sense organs in the head region |
| protonephridia | a simple excretory organ found in planaria |
| spongocoel | the open space inside of a sponge |
| osculum | the opening at the top of a sponge through which water exits the body of the sponge |
| porocytes | cells that have a pore or hole; found in sponges |
| amoebocytes | ameoba like cells found in the mesoglea of sponges |
| mesoglea | a jelly like substace found between the cell layers of sponges and cnidarians |
| spicules | found in the mesoglea of sponges; provides support |
| moneocious | having both male and female sex organs in the same animal |
| dioecious | having male and female sex organs in separate animals |
| gastrovascular cavity | an opening in cnidarians in which digestion occurs |
| cnidocytes | stinging cells found in cnidarians |
| pseudocoelom | a cavity found between the intestine and the body wall in which organs develop; mesoderm is incomplete |
| diploblastic | having two layers of cells |
| triploblastic | having three layers of cells |
| dimorphic | having two different body forms |
| polyp | cnidarian body form in which the tentacles are above the body |
| medusa | cnidarian body form in which tentacles are below the body |
| eucoelom | true body cavity |
