Question

In which group of bilaterians do you find solid bauplan ? Why it is called so ?​

Answer 1

Answer:

Platyhelminthes is the group of bilaterians with solid bauplan. Body cavity is absent in these animals. In these animals, the mesenchyme derived from the third germinal layer, mesoderm occupies the entire blastocoels between the ectoderm and endoderm. As there is no body cavity, the acoelomates exhibit solid body plan.

Answer 2

The Bilaterians which have solid pauplan are Acoelomates.

1) Platyhelminthes are coelomates in which body cavity is absent.

2) In these , the entire blastocoel present between ectoderm and endoderm bis occupied by mesenchyme, derived from mesoderm .

3) The adult platyhelminthes have neither the primary body cavity nor secondary body cavity .

4) In these animals as internal organ embedded in the mesenchyme , they cannot move freely.

5) Diffusion of materials from the gut to the bodywall is made slow and less efficient through mesenchyme .

6) As there is no body cavity the , platyhelminthes have solid pauplan.