Fig. 32-1

1
Fig. 32-1
2
Fig. 32-2-3
Blastocoel
Endoderm
Cleavage
Cleavage
Blastula
Ectoderm
Archenteron
Zygote
Eight-cell stage
Gastrulation
Gastrula
Blastocoel
Blastopore
Cross section of blastula
3
Fig. 32-3
Individual choanoflagellate
Choanoflagellates
OTHER EUKARYOTES
Sponges
Animals
Collar cell (choanocyte)
Other animals
4
Fig. 32-7
(a) Radial symmetry
(b) Bilateral symmetry
5
Fig. 32-8
Coelom
Body covering (from ectoderm)
Tissue layer lining coelom and suspending internal
organs (from mesoderm)
Digestive tract (from endoderm)
(a) Coelomate
Body covering (from ectoderm)
Pseudocoelom
Muscle layer (from mesoderm)
Digestive tract (from endoderm)
(b) Pseudocoelomate
Body covering (from ectoderm)
Tissue- filled region (from mesoderm)
Wall of digestive cavity (from endoderm)
(c) Acoelomate
6
Fig. 32-9
Protostome development (examples
molluscs, annelids)
Deuterostome development (examples
echinoderm, chordates)
(a) Cleavage
Eight-cell stage
Eight-cell stage
Spiral and determinate
Radial and indeterminate
(b) Coelom formation
Key
Coelom
Ectoderm
Mesoderm
Archenteron
Endoderm
Coelom
Mesoderm
Blastopore
Mesoderm
Blastopore
Solid masses of mesoderm split and form coelom.
Folds of archenteron form coelom.
(c) Fate of the blastopore
Anus
Mouth
Digestive tube
Mouth
Anus
Mouth develops from blastopore.
Anus develops from blastopore.
7
Fig. 32-10
Porifera
Cnidaria
ANCESTRAL COLONIAL FLAGELLATE
Metazoa
Ctenophora
Eumetazoa
Ectoprocta
Brachiopoda
Deuterostomia
Echinodermata
Chordata
Bilateria
Platyhelminthes
Rotifera
Protostomia
Mollusca
Annelida
Arthropoda
Nematoda
8
Fig. 32-11
Silicea
Porifera
Calcarea
ANCESTRAL COLONIAL FLAGELLATE
Metazoa
Ctenophora
Cnidaria
Eumetazoa
Acoela
Echinodermata
Deuterostomia
Chordata
Bilateria
Platyhelminthes
Rotifera
Ectoprocta
Lophotrochozoa
Brachiopoda
Mollusca
Annelida
Nematoda
Ecdysozoa
Arthropoda
9
Fig. 32-UN1
Common ancestor of all animals
Sponges (basal animals)
Metazoa
Ctenophora
Eumetazoa
Cnidaria
True tissues
Acoela (basal bilaterians)
Deuterostomia
Bilateria (most animals)
Bilateral summetry
Lophotrochozoa
Three germ layers
Ecdysozoa