1. what special structures are specific to the phylums of porifera, cnidaria, ctenophora, and platyhelminthes?

some of the special structures in the members of these phylum as follows:

Members of porifera are sponges. they have collar cells and cellular -level body organization. Cnidarian have stinging cells present on the tentacles around the mouth. Ctenophorans have comb-like plate cells for swimming. Platyhelminthes - members are first to have sensory and nervous tissue in the head region.