In both mitosis and meiosis the replication of DNA and chromosomes occurs at the same stage.

Answer

**Step-by-Step Solution:**

1. **Understand the Cell Cycle**: The cell cycle consists of several phases: G1, S, G2, and M. Each phase has specific functions related to cell growth and division.

2. **Identify the Phases**:
- **G1 Phase**: This is the first gap phase where the cell grows and duplicates its organelles.
- **S Phase**: This is the synthesis phase where DNA replication occurs, resulting in the duplication of chromosomes.
- **G2 Phase**: This phase involves further cell growth, protein synthesis, and error checking of the DNA.
- **M Phase**: This is the mitotic phase where the cell divides (either through mitosis or meiosis).

3. **Focus on the S Phase**: The question specifically asks about the replication of DNA and chromosomes. This occurs during the S phase of the cell cycle.

4. **Relate to Mitosis and Meiosis**: Both mitosis (cell division for growth and repair) and meiosis (cell division for gamete formation) involve DNA and chromosome replication during the S phase.

5. **Conclusion**: Therefore, in both mitosis and meiosis, the replication of DNA and chromosomes occurs during the S phase of the cell cycle.

**Final Statement**: In both mitosis and meiosis, the replication of DNA and chromosomes occurs in the S phase of the cell cycle.

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