| A | B |
|---|
| third cell layer in the developing embryo | mesoderm |
| body plan of an organism that can be divided along any plane, through a central axis, into roughly equal halves | radial symmetry |
| animal that has three cell layers, w/ a digestive tract but no body cavities | acoelomate |
| single layer of cells surrounding a fluid filled space that forms during early development | blastula |
| animal from which the anus develops from the opening in the gastrula | deuterostome |
| layer of cells on the outer surface of the gastrula | ectoderm |
| body plan of an organism that can be divided down its length into right and left halves that form mirror images | bilateral symmetry |
| body cavity completely surrounded by mesoderm | coelom |
| layer of cells lining the inner surface of the gastrula | endoderm |
| body cavity partly lined with mesoderm such as found in roundworms | pseudocoelom |
| describes organisms that don't move from place to place | sessile |
| embryonic structure of an animal that consist of two cell layers | gastrula |
| animal with a mouth that develops from the opening in the the gastrula | protostome |
| the embryo layer that forms the skin and nervous tissue | ectoderm |
| the animals digestive tract forms from the | endoderm |
| has intracellular digestion | sponge |
| an animal with bilateral symetry | hydra |
| animals w/ bilateral symmetry find food and mates and avoid predators more efficiently because they have | more muscular control |
