The correct sequence of phases of cell cycle is :

Options

A. `G1toStoG_(2)toM`
B. `M toG_(1)toG_(2)toS`
C. `G_(1)toG_(2)toStoM`
D. `StoG_(1)toG_(2)toM`

Answer

To determine the correct sequence of phases of the cell cycle, we can break down the process into clear steps:

### Step-by-Step Solution:

1. **Understanding the Cell Cycle**:
The cell cycle is the series of events that a cell goes through from the moment it is formed until it divides into two daughter cells. It includes phases of growth, DNA replication, and cell division.

2. **Identifying the Phases**:
The cell cycle consists of two main parts: Interphase and the M phase (mitotic phase).
- **Interphase**: This is the preparatory phase where the cell spends about 95% of its time. It is divided into three sub-phases:
- **G1 Phase (Gap 1)**: The cell grows and synthesizes proteins necessary for DNA replication.
- **S Phase (Synthesis)**: The cell replicates its DNA, so each chromosome is duplicated.
- **G2 Phase (Gap 2)**: The cell continues to grow and prepares for mitosis.

3. **M Phase (Mitotic Phase)**:
After interphase, the cell enters the M phase, where it undergoes mitosis (karyokinesis) followed by cytokinesis. Mitosis is further divided into four stages:
- Prophase
- Metaphase
- Anaphase
- Telophase

4. **Correct Sequence**:
Based on the above understanding, the correct sequence of phases in the cell cycle is:
- G1 Phase → S Phase → G2 Phase → M Phase

5. **Conclusion**:
Therefore, the correct answer to the question is the sequence of phases: G1, S, G2, and M.