Structural Organisation in Animals — BIOLOGY STD 11 Science — Question

True metamerism commonly occurs in the arthropods, chordates, and the annelids. While Pseudo-metamerism occurs in the tapeworms etc.

In pseudo-metamerism, segmentation of the ectoderm is the base of metamerism in the complete body. While the segmentation of the mesoderm is the base reason of the segmentation in the True metamerism.

In the pseudo-metamerism, all the segments work as a single unit and they work independently. While in the true metamerism the units work as different units.

True metamerism has the coordination in the segments while the Pseudo-metamerism has zero coordination between the segments.