Which of the following does not occur during mitosis?

Which of the following does not occur during mitosis?

1. Condensation of the chromosomes

2. Replication of the DNA

3. Separation of sister chromatids

4. Spindle formation

5. Separation of the spindle poles

Answer: 2. Replication of the DNA

Mitosis is a process of cell division where one cell, known as the parent cell, divides into two daughter cells and the daughter cells possess the same genetic material as the parent cell. It encompasses a number of important stages but DNA replication is not one of them. DNA replication takes place in the S phase of the cell cycle right before mitosis.

During mitosis, the following events take place:

Condensation of the chromosomes: The duplicated DNA packs into structures that are visible and are called chromosomes.

Spindle formation: The mitotic spindle apparatus forms, which are microtubules that help in the movement of the chromosome.

Separation of sister chromatids: The duplicated chromosomes which are made up of two identical chromatids are then pulled in opposite directions.

Separation of the spindle poles: Mitotic spindle is formed and the spindle poles move towards opposite poles to allow for equal division of genetic material.

Cytokinesis: The cytoplasm divides to give two new daughter cells that are genetically almost identical to the parent cell.

Mitosis cannot occur if the DNA replication has not taken place since each daughter cell has to have the full set of chromosomes. However, the actual replication process takes place during the cell cycle before the mitosis not in the process of mitosis itself.