INVERTEBRATE DIVERSITY SECTION (Biol.201), Spr 2000
Dr. Kathy S. Williams (email
kwilliams@sunstroke.sdsu.edu)Return to
Invertebrate Introduction Go to next topic Return to SyllabusMatrix of animals without a true coelom:
Material presented in class on Monday, 3/20/00.
In class we filled in this chart; practice making charts like this and filling them in to study in a comparative way.
However, don’t stop after ‘memorizing’ information in a table like this.
• Ask yourself if the characteristics allow the animals to do something different than other
• Ask if the characteristics are found in ancestral forms or not.
• Be able to explain what animals are more closely related to one another ? and why.
Note that I’ve used short hand on this chart. In a complete answer you must spell out words to demonstrate your complete understanding.
Included in this table are only a few of the many categories you might use for comparisons ? add more to help you study (you might add modes of reproduction, for example).
|
PORIFERA |
CNIDARIA |
PLATYHELMENTHES |
NEMATODA |
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SYMMETRY |
none |
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|
bilateral |
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BODY FORM /CAVITY? |
cellular organization; no cavity |
polyp/medusa; no cavity |
|
pseudocoelomate |
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EMBRYONIC TISSUE LAYERS |
none |
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|
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DIGESTION |
cellular |
|
gastrovascular cavity |
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CIRCULATION |
no syst/aquiferous system |
none/cellular |
none |
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RESPIRATION |
cellular/body surface |
cellular/body surf |
cellular/body surf |
cellular/body surf |
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MOVEMENT |
none |
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|
longitudinal muscles |
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NERVOUS SYSTEM |
none |
nerve net; cells |
|
2 lateral nerve cords |
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HABITAT |
aquatic (marine) |
aquatic (marine) |
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parasitic; aquatic (terrestrial) |
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EXCRETION |
none/cellular |
none/cellular |
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SKELETON |
spicules; spongin |
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hydrostatic |
hydrostatic |
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SPECIALTIES? |
totipotent (know meaning ...) |
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