The mitotic cell cycle: outline question

A biologist observes a population of human skin stem cells under a microscope. She notes that some cells are in interphase and others are in mitosis. Outline the sequence of phases in the mitotic cell cycle of a skin stem cell, describing the key events that occur in each phase. In your answer, refer to the structure of chromosomes, the role of telomeres, and the importance of mitosis for tissue maintenance. Explain how a failure to control the cell cycle could lead to a tumour.