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Author Question: Planarians lack dedicated respiratory and circulatory systems because A) none of (Read 1105 times)

Charlie

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on: Aug 5, 2013
Planarians lack dedicated respiratory and circulatory systems because
A) none of their cells are far removed from the gastrovascular cavity or from the external environment.
B) they lack mesoderm as embryos and, therefore, lack the adult tissues derived from mesoderm.
C) their flame bulbs can carry out respiratory and circulatory functions.
D) their body cavity, a pseudocoelom, carries out these functions.


camila

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Reply #1 on: Aug 8, 2013
Answer has to be A, trust me!


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Charlie

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Reply #2 on: Oct 18, 2013
Wonderful, you were right, thank you so much.


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