Classification, Phylogeny, &
Organization
Chapter 7 Notes
Classification Review
• Taxonomic Hierarchy
• Nomenclature
Review
• What are the three Domains?
• What are the six Kingdoms?
Domains & Kingdoms
Bacteria
Archea
Eukarya
Bacteria
Archea
Plantae
Fungi
Protista
Animalia
Eukaryotes
Plantae
Fungi
Protista
Animalia
Multicellular
Multicellular
Unicellular
Multicellular
Cell wall
Cell wall
Some have cell wall
No cell wall
Autotrophic
Heterotrophic
Auto/Heterotrophic Heterotrophic
Non motile
Non motile
Motile
Motile
Patterns of Organization
• Symmetry – parts of an organism are equally
arranged around a point or axis
– Bilateral symmetry:
• A single plane divides the organism into right and left mirror
images
– Ex: humans, dogs, fish, kangaroo , vertebrates
– Radial symmetry:
• Any plane passing through the central axis divides the
organism into a mirror image
– Ex: Sea Urchins, Jelly Fish, sea anemones, Echinoderms
– Sea Star = “Penta-radial”
• Asymmetry – absence of symmetry
– Ex: sponges
Cephalization
• The formation of a distinct head
• Only occurs in animals
Terms of Direction
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Aboral – End opposite of mouth
Oral – Mouth end
Anterior – front
Posterior – behind
Dorsal – backside
Ventral – belly side
Cephalic – towards head
Caudle – towards tail
Superior – above
Inferior – below
Medial – along the symmetry plane
Lateral – away from the symmetry plane
Distal – away from point of attachment
Proximal – toward point of attachment
Other Patterns of Organization
• Unicellular Level of Organization
– Protists
– Must provide for the functions of
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Locomotion
Food acquisition
Digestion
Water and ion regulation
Sensory perception
Reproduction
• Diploblastic Level of Organization
• Triploblastic Level of Organization
Diploblastic Organization
• Simplest tissue-level organization
• Tissues derived from two
embryological layers
– Ectoderm – gives rise to epidermis;
outer layer
• Epithelial cells - the epidermis or skin
• Brain
• nervous system
– Endoderm – gives rise to
gastrodermis, tissue that lines the
gut cavity
• lining of the stomach & intestines
– Middle Layer = Mesoglea; noncellular
Triploblastic Organization
• Tissues derived from three embryological
layers
– Ectoderm
– Mesoderm – gives rise to supportive tissues
(bones), contractile tissues (muscles), and
blood cells.
– Endoderm
– Most organisms with this level of
organization develop organ systems.
• Excretory, nervous, digestive, reproductive,
circulatory systems
Triploblastic Animals are further
Organized based on…
Presence or Absence of a
Body Cavity
• Acoelomate – solid
mass/without cavity
• Pseudocoelomate - body
cavity not entirely lined
by mesoderm
• Coelomate – body cavity
completely surrounded
by mesoderm
Coelom = Cavity
Protostomes & Deuterostomes
Protostomes
• Mouth forms from an
embryonic blastopore
– Blastopore: an indention in
the blastula
– Blastula: an early stage in the
development of an embryo
• Sphere of cells enclosing a
fluid filled cavity
• Ex: Platyhelminthes,
Nematodes, Molluscs,
Annelids, and Arthropods
Deuterostomes
• Anus forms from an
embryonic blastospore
• Ex: Echinoderms,
Hemichordates, Chordates