Question

Ascaris is characterized by the

• A. presence of true coelom and metamerism
• B. presence of metamerism only
• C. presence of neither true coelom nor metamerism
• D. presence of true coelom but an absence of metamerism

Answer 1

The correct option is C presence of neither true coelom nor metamerism

Ascaris belongs to phylum Aschelminthes. It is characterized by the presence of pseudocoelom and an absence of metamerism. In pseudocoelomates, the body cavity is not lined by mesoderm. Instead, they have a false fluid-filled cavity.

Metamerism is the external and internal division of the body into segments with a serial repetition of organs in each segment.

Presence of true coelom and metamerism is a characteristic feature of the members of the phylum Annelida such as earthworms.

Presence of true coelom and absence of metamerism is exhibited by the organisms such as snails, mussels, starfish, etc.

Animals belonging to the phylum Porifera and Coelenterata do not have true coelom and metamerism.