The different stages of the mitotic cell cycle comprise prophase, metaphase, anaphase and telophase. Prophase: Condensation of the chromosomes and the mitotic spindle begins to form. The spindle is composed of microtubules. The nucleus starts to break down. At the end of the prophase some of the mitotic spindles start to attach to chromosomes and the nuclear envelope breaks down. Metaphase: The spindle apparatus is fully built and attached to the chromosomes. The chromosomes are lined up at the metaphase plate. Before moving to the next step, the cells checks at a so called checkpoint whether everything is aligned properly.Anaphase: In this step, the sister chromatids separate from each other and are pulled towards opposite ends of the cell. This process is enabled via motor-proteins that use microtubules for guidance. Telophase: As the cell is almost done dividing, the mitotic spindle is broken down, two new nuclei form and nuclear membranes and nucleoli reappear. Other cell organs and contents are also divided between the two cells. The chromosomes decondense again.The cells separate in a step called cytokinesis.