Question

their skeleton is made up of calcareous plates of spicules

Answer 1

HEYA!

SOLUTION

As a whole, poriferans have diverse skeletal elements including calcareous laminae, organic filaments, and siliceous and calcareous spicules. ... Some spicules are formed of the mineralized substances calcium carbonate and silica, while others are made of an organic substance called spongin.

HOPE THIS HELPS

:)