Human skin is composed of numerous layers of epithelial cells. The innermost layer of cells is composed entirely of stem cells while the outer layers are differentiated. A stem cell separates to generate two cells, one of which remains a stem cell and the other differentiates to become the mature skin cell. Hypothesize a scenario which could occur inside the skin stem cell that would cause only one of two cells produced by division of the stem cell to differentiate. Include what’s going on at the level of RNA, DNA, and proteins which makes the cell differentiated.
You don’t need to learn all about how skin cells operate to answer this problem. Consider the skin stem cell to be similar to other stem cells and prepare down the generic argument (make it up) about how stem cells can manufacture one differentiated cell and one cell that remains the stem cell.