How useful is the study of the nature of body cavity and coelom in the classification of animals?
Explanation Body cavity or a coelom is the space between the digestive tract and the body wall. On the basis of presence or absence of body cavity, animals are classified into three categories: coelomates, acoelomates and pseudocoelomates. Coelomates: Those animals which posses true coelom are known as coelomates. For examples: phylum annelid, arthropods and mollusks and all vertebrates. Acoelomates: Those animals which does not contains true body cavity or coelom are called acoelomates. For example: platyhelminthyes which include flatworms. Pseudocoelomates: Those animals which contain false cavity or a cavity filled with body fluid are called pseudocoelomates. For example: phylum nematode which include roundworms. Final Answer Animals are classified as coelomates (those which contains true coelom), acoelomates (those which does not contain body cavity or coelom) and pseudocoelomates (those which has a fluid filled cavity).
