What is the relationship between germinal layers and the formation of the body cavity in case of coelomate, acoelomates and pseudocoelomates?
Germinal layers are those which formed during the process of gastrulation. The outer layer of germ is called ectoderm, the middle one is endoderm and the innermost
is the endoderm. Coelomates are the organisms possessing coeloms. The coelom is the body cavity lined by the mesoderm. Examples of coelomates are phylum
Annelida, Mollusca, arthropods, etc. The organisms with absent body cavities are called coelomates. E.g. Platyhelminthes. Some of the organisms do not have a lining
by mesoderm. Instead of that, it will be in the form of a scattered pouch in between ectoderm and endoderm. Such a body cavity is called pseudocolour and animals
possessing pseudocoelom are referred to as pseudocoelomates e.g., Ascaris.