What makes the phylum of Platyhelminthes more complex than the Cnidarians? Organisms in the phylum Platyhelminthes are triploblastic, this means they have 3 germ layers. This is a step up from the Cnidarians 2 germ layers, however they still have no coelom. The biggest difference between the 2 phylums is that organisms belonging to the Platyhelminthes phylum are cephalized. this means they have all there sensory organs in the anterior end of their bodies. Platyhelmenthians also have a digestive track with an anterior opening and a posterior opening so food goes in one end and comes out another, much like us. However the organisms done have a complete digestive system with muscles around it able to squeeze and contract so they can not control when they excrete waste. This is a major step up from the Cnidarians digestive system with one opening and a large gastrovascular cavity.
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Platyhelminthes V.s. CNidaria |