Sponges (phylum: porifera) are animals that possess feeding cells called collar cells. these cells have a central flagellum surrounded by a collar of microvilli. the collar filters organic matter out of the water column. which protist shares a more recent common ancestor with the poriferans? question 4 options: a. rhodophyta b. choanoflagellates c. myxomycota d. radiolarians e. ciliates save