What has not germ layers, not gut and no distinct cleavage pattern?
Porifera
The organisms that do not possess germ layers, gastrointestinal tract (gut), and distinct cleavage pattern are called sponges or Porifera. Sponges are multicellular, but they do not have tissues and organs like other animals. Instead, their body is made up of a gelatinous substance called mesohyl that surrounds a central cavity called spongocoel, which functions as the gut. Sponges do not have a distinct cleavage pattern during embryonic development. They exhibit cellular differentiation, but not in the same way as the germ layers of other animals. Instead, the cells of a sponge differentiate as needed to perform various functions, but these cells are not organized into tissues. Overall, sponges represent a unique and primitive branch of the animal kingdom.
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