The simplest type of canal system in Porifera is:

What type of body organization is found in animals of the phylum $Porifera$?

In Porifera,the spongocoel is lined by flagellated cells called . . . . . . .

What is the location and function of collar cells?

Body having meshwork of cells,internal cavities lined with food filtering flagellated cells and indirect development are the characteristics of Phylum

Which of the following are 'multicellular grade' organisms?