| A | B |
|---|
| desmosomes | cell arranged with anchor proteins that attach different layer of tissue, common in heart and skin |
| gap junction | cells specifically arrangement with a space between them to allow for chemical passage |
| collagen | long fibrous protein in the intercellular matrix that binds cell together |
| proteoglycans | part of the intercellular matrix, play a role in cellular communication and nutrient distribution |
| Hox gene | bundle of regulatory genes involved in the coordination of a head-tail body arrangement in animals |
| choanoflagelates | protist ancestor of animals shares many external features with sponges |
| mesoderm | middle germ layer that differentiates into muscle and bone |
| ectoderm | outer germ layer that differentiates into skin and nerve tissue |
| endoderm | inner germ layer that differentiates into internal organs |
| coelum | the tube formed in gastrulation that becomes some form of digestive cavity in most animals |
| diploblastic | organisms which form from two embryonic germ layers |
| triploblastic | organisms which form from three embryonic germ layers |
| deuterostome | organisms in which the blastopore becomes the anus |
| protostome | organisms in which the blastopore becomes the mouth |
| notochord | stiff, internal rod that from which chordates get their internal structure |
| bilateral symmetry | body arrangement in which left and right form mirror images |
| radial symmetry | symmetric body arrangement around a single axis and one focus point |
| segmentation | separate body regions in certain animals that provide for a greater range of motion and appendages |
| blastula | round, hollow ball of embryonic cells which begin the animals body plan |
| ecdysozoa | animals which must molt their shell, exoskelleton or cuticle to grow |
