During which stage of the cell cycle is cell growth and replication of organelles most significant?

Options

A. M phase
B. `G_1` phase
C. `G_2` phase
D. S phase

Answer

To determine during which stage of the cell cycle cell growth and replication of organelles are most significant, we can analyze the different phases of the cell cycle:

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

2. **G1 Phase**:
- The G1 phase (Gap 1) is primarily focused on cell growth.
- During this phase, the cell is metabolically active and is involved in the duplication of organelles and cytosolic components.
- This is a critical phase for preparing the cell for DNA synthesis.

3. **S Phase**:
- The S phase (Synthesis) is where DNA replication occurs.
- The chromosomes are duplicated, but this phase is not primarily about organelle replication.

4. **G2 Phase**:
- The G2 phase (Gap 2) continues cell growth and involves the synthesis of proteins and enzymes.
- It also includes a final check of the DNA before the cell enters mitosis, but organelle replication is not the main focus.

5. **M Phase**:
- The M phase (Mitosis) is where nuclear division occurs.
- This phase does not involve significant growth or organelle replication.

6. **Conclusion**:
- Based on the analysis, the G1 phase is the stage of the cell cycle where cell growth and organelle replication are most significant.

**Final Answer**: The stage of the cell cycle where cell growth and replication of organelles are most significant is the **G1 phase**.

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