Which event does not take place before the start of mitosis?

• A. Chromosome condensation
• B. Cell growth
• C. DNA replication
• D. Centrosome duplication

Answer: (A)

Verified step by step guidance

1. Understand the context of the question: Mitosis is the process of cell division that results in two daughter cells with identical genetic material. Before mitosis begins, the cell undergoes several preparatory steps during interphase.
2. Identify the key events that occur during interphase, which is the phase before mitosis: These include cell growth, DNA replication, and centrosome duplication.
3. Cell growth occurs during the G1 phase of interphase, where the cell increases in size and prepares the necessary components for DNA replication.
4. DNA replication takes place during the S phase of interphase, where the cell's DNA is duplicated to ensure that each daughter cell will have a complete set of chromosomes.
5. Centrosome duplication occurs during the G2 phase of interphase, preparing the cell for the formation of the mitotic spindle during mitosis. Chromosome condensation, however, is a process that occurs at the beginning of mitosis, specifically during prophase, and not before mitosis starts.