| A | B |
|---|
| vertebrate | animal with dorsal nerve cord |
| invertebrate | animal without dorsal nerve cord or spine |
| specialization | the differentiation of cell for a particular function |
| differentiation | process in which the cells in a multi-cellular individual becomes specialized during development |
| radial symmetry | animal with arrangement of body parts around a central axis |
| dorsal | top side of bilaterally symmetrical animal |
| ventral | bottom side of bilaterally symmetrical animal |
| anterior | head end (front end) – area of concentration of sensory organs |
| posterior | back end of bilaterally symmetrical animal |
| bilateral symmetry | body plan in which the left and right hand side mirror each other |
| cephalization | concentration of nerve tissue and sensory organs towards the anterior end of an organ |
| germ layer | vertebrates have three; invertebrates have two |
| endoderm | inside germ layer that forms digestive system |
| ectoderm | outside and forms nervous system and sensory organs, |
| mesoderm | middle forms skeletal system and skin – these layers are found in embryonic stage and specialize to form organs and systems |
| chordates | have notochord with dorsal nerve cord |
| segmentation | repeating similar units; regeneration can occur from segments – first sign of organization |
| exoskeleton | rigid outer covering protecting tissues of invertebrates - chitin |
| gas exchange | CO2 exchanged from inside out and O2 taken into body tissues |
| gills | organs specialized for gas exchange in water and filter feeding |
| circulatory system | distributes oxygen and nutrients to cells throughout the body |
| open circulatory system | give example system in which the fluid is not contained in vessels |
| closed circulatory system | circulatory system with true blood and travels through true vessels |
| hermaphrodite | having both sexual characteristics – both male and female gametes are made in same body |
| larvae | free living immature form of organism |
| endoskeleton | internal skeleton that can support a large and heavy body |
