Diploblastic organisms are organisms which evolve from an ovum, and include cnidarian and ctenophores.Diploblasty is a condition of the ovum in which there are 2 primary germ layers:the ectoderm and endoderm
All the more complex animals(from flat worms to man) are triploblastic with three germ layers.Triploblasty is a condition ot the blastula in which there are 3 primary germ layers.