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Why are sponges considered less complex than cnidarians?

Sponges are basically just a collection of cells living together. They have no real tissues. Cnidarians have simple tissues. Neither have a gut.


Sponges are multicellular, but do have a very simple grade of organization. The body is made up of loosely connected cells which are embedded in a gelatinous matrix. Sponges lack real organs or true tissues. Cnidarians have two true tissue layers (an outer epidermis and an inner gastrodermis) separated by a connective tissue layer called the mesoglea.The nervous system of cnidarians consists of a diffuse network of neurons called a nerve net in which any direction of conduction is possible.

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