"Post-mitotic phase" of the cell in which active synthesis of RNA and proteins takes place is:

Options

A. `G_(1)`-phase
B. Amitotic phase
C. `G_(2)` -phase
D. S-phase

Answer

To determine the "post-mitotic phase" of the cell in which active synthesis of RNA and proteins takes place, we need to analyze the cell cycle and its phases.

### Step-by-Step Solution:

1. **Understanding the Cell Cycle**: The cell cycle consists of a series of events that a cell goes through as it grows and divides. It is divided into two main phases: Interphase and M phase (Mitotic phase).

2. **Identifying Interphase**: Interphase is the longer phase of the cell cycle, comprising about 95% of the cycle. It is further divided into three sub-phases: G1 (Gap 1), S (Synthesis), and G2 (Gap 2).

3. **Recognizing the M Phase**: The M phase, which includes mitosis and cytokinesis, is the shorter phase of the cell cycle, accounting for about 5% of the cycle. This is where the cell divides.

4. **Post-M Phase Transition**: After the M phase, the cell enters the G1 phase of Interphase. This is the period immediately following mitosis.

5. **Active Synthesis in G1 Phase**: During the G1 phase, the cell is actively synthesizing RNA and proteins. This is a crucial time for the cell as it prepares for DNA replication in the S phase.

6. **Conclusion**: Therefore, the post-mitotic phase in which active synthesis of RNA and proteins occurs is the **G1 phase**.

### Final Answer:
The post-mitotic phase of the cell in which active synthesis of RNA and proteins takes place is the **G1 phase**.