Question

In contrast to the Annelids, the Platyhelminthes show:

• A. Radial symmetry
• B. Absence of body cavity
• C. Bilateral symmetry
• D. Presence of pseudocoel

Answer 1

The correct option is B

Absence of body cavity

In annelids, the body cavity is lined by the mesoderm and they are coelomates. In case of Platyhelminthes, the body cavity is not lined by the mesoderm, but the mesoderm is present in pouches between the ectoderm and the endoderm. Hence, they are called pseudocoelomates.