Symmetry

1
Symmetry
2
Spherical Symmetry
blastula
3
Asymmetrical
(no symmetry)
(ectoderm)
sponges
4
Radial Symmetry
(ectoderm and endoderm)
jellyfish
5
Bilateral Symmetry
(ectoderm, mesoderm, endoderm)
roundworm
flatworm
6
Body Plan 0
Development stops at blastula stage.
Ectoderm is only germ layer.
No symmetry (asymmetrical)
sponges
7
Body Plan 1
Development stops at gastrula stage.
Only ectoderm and endoderm.
Radial symmetry
cnidarians
8
Body Plan 2
Development stops at gastrula stage.
Ectoderm, endoderm, and mesoderm.
Bilateral symmetry
flatworms
9
Body Plan 3
(pseudocoelomates)
Development beyond gastrula stage.
Ectoderm, endoderm, and mesoderm.
Also a body cavity (pseudocoelom).
roundworms
10
Body Plan 4
(coelomates)
Development beyond gastrula stage.
Ectoderm, endoderm, and mesoderm.
Also a body cavity (coelom)
All higher animals
crab
leech
11
Plan 1
Plan 2
Plan 4
Plan 3