In biology, Mitosis is the process of chromosome segregation and nuclear division that follows replication of the genetic material in eukaryotic cells. In S phase, the cell starts to synthesize the DNA and completes preparation for cell division. In the G1 phase which is also called the “first gap” the cell grows as it copies its chromosomes. This phase is where the cell grows and copies its chromosomes in preparation for cell division. The interphase cycle accounts for about 90% of the cell cycle. The mitotic phase which includes both mitosis and cytokinesis is the shortest part of the cell cycle.

Mitosis divides genetic information during cell division. The process of mitosis ends after the nuclei have reformed and the cell membrane begins to separate the cell into two daughter cells, during cytokinesis. As the separated chromatids, now termed chromosomes, reach the poles, the cell will enter telophase and nuclei will start to reform. As the cell enters anaphase, the chromatids, which form the chromosomes, will separate and drift toward opposite poles of the cell. (Some biology textbooks insert a phase called 'prometaphase' at this point.)The second step, known as metaphase, occurs when all the chromosomes are aligned in pairs along the midline of the cell. The first step of cell division is prophase, during which the nucleus dissolves and the chromosomes begin migration to the midline of the cell. Before the cells can divide, the chromosomes will have duplicated and the cell will have twice the normal set of genes. Mitosis is the normal type of cell division.

Define prophase