The Flatworms are More Derived (Or Advanced)than the Cnidarians Because

Question

The flatworms are more derived (or advanced)than the cnidarians because of their
A)circulatory and digestive systems.
B)circulatory and respiratory systems.
C)excretory and nervous systems.
D)respiratory and digestive systems.

Accepted Answer

The flatworms have a more advanced excretory and nervous system compared to the cnidarians. Flatworms have flame cells that help in excretion of metabolic waste and a nerve net that allows for more complex behaviors. Cnidarians, on the other hand, lack a true excretory system and have a simple nerve net. Therefore, option C is the best choice. Options A, B, and D are incorrect because they do not accurately differentiate the two groups.