The following diagram shows the branching tree for four kingdoms and some of their shared derived characteristics. A slanting line is shown. There are four lines drawn vertically on this line at equal intervals. There is a black circle between each pair of these vertical lines. Protists, Plants, Fungi, Animals are written on top of each vertical line in order from left to right. Common Cell is written on the left most end of the sloping line. The second black circle has Mostly Multicellular written on it. The first black circle has X written on it.

What shared characteristic can be written at point X? Use complete sentences to explain your answer.