Question

what is a colonial organism?why are colonial organisms not classified as multicellular despite having many cells?

Answer 1

Colonial organisms are clonal colonies composed of many physically connected, interdependent individuals. The subunits of colonial organisms can be unicellular, as in the alga Volvox (a coenobium), or multicellular, as in the phylum Bryozoa.

If some members of the aggregation carry out functions that others cannot, so their respective contributory functions are each necessary to the survival of the whole, then it is a multicellular organism.

Answer 2

Colonial organisms are clonal colonies composed of many physically connected, interdependent individuals. The subunits of colonial organisms can be unicellular, as in the alga Volvox (a coenobium), or multicellular, as in the phylum Bryozoa. The former type may have been the first step toward multicellular organisms.