What is one characteristic that all protists do you have in common

1) cnidarians have bilateral symmetry, 2) there are 2 different forms (dimorphism), a medusa and a polyp, 3) reproduction is asexual or sexual. 4) they have cnidoblasts, special cells that contain nematocysts, the cells that sting, and 5) they have an internal cavity, and a mouth where food comes in and out. digestion is extracellular.