In a mitotic cycle,the correct sequence of phases is

Options

A. S,G1,G2,M
B. G1,S,G2,M
C. M,G1,G2,S
D. G1,G2,S,M

Answer

To determine the correct sequence of phases in a mitotic cycle, we need to understand the structure of the cell cycle. The cell cycle consists of several phases that prepare a cell for division. Here’s a step-by-step breakdown:

### Step 1: Identify the Phases of the Cell Cycle
The cell cycle is divided into two main parts: Interphase and the Mitotic phase (M phase). Interphase itself is further divided into three phases:
1. **G1 Phase (Gap 1)**: The cell grows and carries out normal metabolic processes.
2. **S Phase (Synthesis)**: DNA replication occurs, resulting in the duplication of chromosomes.
3. **G2 Phase (Gap 2)**: The cell continues to grow and prepares for mitosis, including protein synthesis.

After Interphase, the cell enters the M phase, where mitosis occurs.

### Step 2: Sequence the Phases
The correct order of the phases in the cell cycle is:
1. **G1 Phase**
2. **S Phase**
3. **G2 Phase**
4. **M Phase**

### Step 3: Verify the Options
Now, let's analyze the options given in the question:
1. **Option 1**: S, G1, G2, M - Incorrect
2. **Option 2**: G1, S, G2, M - Correct
3. **Option 3**: M, G1, G2, S - Incorrect
4. **Option 4**: G1, G2, S, M - Incorrect

### Conclusion
The correct sequence of phases in a mitotic cycle is **G1, S, G2, M**. Therefore, the correct answer is **Option 2**.

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