Not sure if I'm correct but my best guess is the cell membrane seeing as it surrounds the cell itself and is responsible for allowing certain molecules to diffuse in or out of the cell. Good Luck! :)
This resemblance confers an advantage upon one or both organisms by which the ... Other inedible species resembling the first.
That would be called <span>Defecation.</span>
The difference between a multicellular organism and a colonial organism is that individual one-celled organisms from a colony can, if separated, survive on their own. so yes colonial organisms can live on their own.