Which of the following is characteristic of cilia? They are whiplike, motile cellular extensions that occur in large numbers on the exposed surfaces of certain cells. They are used for cellular adhesion. They are substantially longer then flagella, and are less common than flagella in humans. They move substances in many directions across a cell\'s surfaces. Solution They are whip like motile cellular extensions that occur in large numbers on the exposed surfaces of certain cells. They are little appendages that stick out from eukaryotic cells,whereas only one or two of them would be called flagella..