The document discusses the hierarchical organization and architectural patterns of animals. It outlines five major grades of organizational complexity - from single-celled organisms to multicellular organisms with organ systems. Additionally, it describes the three main types of symmetry seen in animals - spherical, radial, and bilateral - and the three coelomic arrangements of triploblasts - acoelomate, eucoelomate, and pseudocoelomate. Segmentation is also noted as a pattern seen in some animal bodies.

1. Architectural Patterns of
Animals

2. Architectural Patterns of Animals
Hierarchical Organization of Complexity
- Five (5) major grades of organization
- Each successive grade is more complex than and builds on the preceding ones
- Unicellular eukaryotes
- Within single cell all functions of life performed
1. Protoplasmic Grade
- No cellular specialization
- Organelles perform specialized functions
- Single-celled protists and many colonial protists
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3. Architectural Patterns of Animals
Hierarchical Organization of Complexity
- Five (5) major grades of organization
- Each successive grade is more complex than and builds on the preceding ones
2. Cellular grade
- Multicellular organisms
- Cell specialization
- Cells cannot survive apart from the whole
- Sponges, some colonial protists
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4. Architectural Patterns of Animals
Hierarchical Organization of Complexity
- Five (5) major grades of organization
- Each successive grade is more complex than and builds on the preceding ones
3. Cell-tissue grade
- Eumetazoans
- Cells with same function aggregate into tissues.
- No organs
- Cnidarians (jellies and allies)
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5. Architectural Patterns of Animals
Hierarchical Organization of Complexity
- Five (5) major grades of organization
- Each successive grade is more complex than and builds on the preceding ones
4. Tissue-organ grade
- Tissues arranged into organs
- Parenchyma and stroma
- Platyhelminthes
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6. Architectural Patterns of Animals
Hierarchical Organization of Complexity
- Five (5) major grades of organization
- Each successive grade is more complex than and builds on the preceding ones
5. Organ system grade
- Organs work together
- Familiar organ systems
- Most animal phyla at this grade
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7. Architectural Patterns of Animals
Animal Symmetry
- Spherical symmetry - any plane
passing through the center
creates mirrored halves
- Best suited for floating or rolling
- Some protists
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8. Architectural Patterns of Animals
Animal Symmetry
- Radial symmetry - two or more
planes passing through
longitudinal axis produce
mirrored halves
- Motile or sessile
- Often tubular, vase, or bowl-
shaped
- Cnidarians, echinoderms, some
sponges
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9. Architectural Patterns of Animals
Animal Symmetry
- Radial symmetry - two or more
planes passing through
longitudinal axis produce
mirrored halves
- Variants include biradial symmetry (ctenophores)
and pentaradial symmetry (echinoderms)
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10. Architectural Patterns of Animals
Animal Symmetry
- Bilateral symmetry - only capable
of being divided along sagittal
axis into two mirrored halves
- Majority of animals
- Cephalization
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11. Architectural Patterns of Animals
Body Cavities and Germ Layers
- Body cavity - any internal, open
space
- Gut (digestive tract) is an obvious
example
- Many animals have a second
cavity
- Following the blastula stage, cells
differentiate into germ layers
- Gastrula now formed
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12. Architectural Patterns of Animals
Body Cavities and Germ Layers
- Diploblasts have two germ layers
- Ectoderm, endoderm
- Triploblasts have three germ
layers
- Ectoderm, endoderm, and
mesoderm
- Mesoderm forms by 1 of 2 plans
- Schizocoelous
- Enterocoelous
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13. Architectural Patterns of Animals
Body Cavities and Germ Layers
- Diploblasts have two germ layers
- Ectoderm, endoderm
- Triploblasts have three germ
layers
- Ectoderm, endoderm, and
mesoderm
- Mesoderm forms by 1 of 2 plans
- Schizocoelous
- Enterocoelous
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14. Architectural Patterns of Animals
Triploblasts and the Coelom
- Three coelomic arrangements
are recognized
- Coelom - fluid-filled cavity
completely surrounded by
mesoderm
- Acoelomate - mesoderm cells
completely fills the blastocoel,
no coelom present
- Phyla Platyhelminthes,
Acoelomorpha, Gnathostomulida,
Nemertina, Mesozoa. All are
protostomes.
Ectoderm
Mesoderm
Endoderm
Gut cavity
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15. Architectural Patterns of Animals
Triploblasts and the Coelom
- Three coelomic arrangements
are recognized
- Coelom - fluid-filled cavity
completely surrounded by
mesoderm
- Eucoelomate - coelom presents,
completely surrounded by
mesoderm
- Phyla - all deuterostomes, many
protostomes
Ectoderm
Mesoderm
Endoderm
Gut cavity
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16. Architectural Patterns of Animals
Triploblasts and the Coelom
- Three coelomic arrangements
are recognized
- Coelom - fluid-filled cavity
completely surrounded by
mesoderm
- Pseudocoelomate - false coelom
present, incompletely
surrounded by mesoderm
- Phyla - many protostomes
Ectoderm
Mesoderm
Endoderm
Gut cavity
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17. Architectural Patterns of Animals
Segmentation
- Some animal bodies are
composed of repeated segments
(metameres)
- Phylum Annelida,
- Arthropoda, Chordata
- Obvious in first two, less so in
third
- Permits greater mobility and
complexity
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