Answer :
Triploblastic animals are divided into three groups based
on the presence or absence of an embryonic body cavity called coelom.
1.Acoelomata - no coelom Ex : Platyhelminthes
2. Pseudocoelomata - with a false coelom Ex : Nematoda
3. Coelomata - with a true coelom
1.Acoelomata - no coelom Ex : Platyhelminthes
2. Pseudocoelomata - with a false coelom Ex : Nematoda
3. Coelomata - with a true coelom
By the broadest definition, a body cavity is any fluid-filled space in a multicellular organism, other than those of vessels.