Which one is false about `G_(1)`-phase (Gap-I)?

Options

A. lt occurs between M and S phase
B. In it cells are metabolically active and continuously grow
C. It is pre-synthetic or post mitotic phase
D. In this phase DNA synthesis

Answer

To determine which statement about the G1 phase (Gap 1 phase) is false, we first need to understand the characteristics of the G1 phase in the cell cycle. Here’s a step-by-step breakdown:

### Step 1: Understanding the Cell Cycle
The cell cycle consists of several phases:
1. **G1 Phase (Gap 1)** - The cell grows and prepares for DNA synthesis.
2. **S Phase (Synthesis)** - DNA replication occurs.
3. **G2 Phase (Gap 2)** - The cell continues to grow and prepares for mitosis.
4. **M Phase (Mitosis)** - The cell divides.

### Step 2: Characteristics of G1 Phase
- The G1 phase is the first phase after mitosis (M phase).
- During G1, the cell is metabolically active, growing, and synthesizing proteins necessary for DNA replication.
- It is a pre-synthetic phase, meaning it occurs before the S phase where DNA synthesis takes place.

### Step 3: Identifying the False Statement
In the context of the question, we need to evaluate statements about the G1 phase. The provided video transcript mentions:
- DNA synthesis occurs in the S phase, which is true.
- G1 phase is pre-synthetic and post-mitotic, which is also true.
- Cells are metabolically active and continuously grow during G1, which is true.
- G1 phase occurs between M phase and S phase, which is true.

Since all statements mentioned in the video transcript about the G1 phase are correct, we can conclude that any statement claiming otherwise would be false.

### Conclusion
The false statement about the G1 phase is that DNA synthesis occurs during G1; it actually occurs during the S phase.

### Final Answer
The false statement about the G1 phase is that DNA synthesis occurs in the G1 phase; it occurs in the S phase.

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