In this phase, the nucleus, or chocolate chip, is just part of a growing cell. Soon, the cell's (cookie's) DNA copies to prepare for dividing.
Prophase is the first step of Mitosis. Here, the nucleus begins to divide. Centrioles become visible to the eye, moving to opposite ends of the cell with spindle fibers connecting them. The nuclear membrane dissolves.
Metaphase is the second step. Chromatids move to the center of the cell, and are attached to spindle fibers. These are easily recognized. The nucleus seperates.
Anaphase is the stage of Metosis where the sister chromatids separate. They become "daughter chromosomes" and move to opposite ends of the cell.
Telophase is the final stage. The new, complete nuclei form, and chromosomes appear as chromatin. Daughter chromosomes are not visible, and form a nuclear membrane around each group.
Cytokinesis is the final stage. Either a cell wall or cell membrane form, separating the two cells. Both have their own nucleus and identical chromosomes. Yay, now we have two cookies from one!