Arrange the following events of mitotic cell cycle in correct sequence
I. Initiation of spindle formation
II. DNA replication
III. Disappearance of Golgi complex, E.R and nuclear membrane
IV. Movement of chromosome towards the poles
V. Decondensation of chromosomes

Options

A. II, III, I, V
B. II, I, III, IV, V
C. II, IV, III, I, V
D. V, IV, III, I, II

Answer

To arrange the events of the mitotic cell cycle in the correct sequence, we need to understand the phases of the cell cycle and the order of events that occur during mitosis. Here’s the step-by-step solution:

### Step 1: Identify the phases of the cell cycle
The mitotic cell cycle consists of several phases:
- Interphase (which includes G1, S, and G2 phases)
- Mitosis (which includes prophase, metaphase, anaphase, and telophase)

### Step 2: Analyze each event
1. **DNA Replication (II)**: This occurs during the S phase of interphase, where the DNA is duplicated.
2. **Initiation of spindle formation (I)**: This begins in prophase, where the spindle apparatus starts to form.
3. **Disappearance of Golgi complex, E.R, and nuclear membrane (III)**: This occurs during prophase as the cell prepares for mitosis.
4. **Movement of chromosomes towards the poles (IV)**: This happens during anaphase when the sister chromatids are pulled apart towards opposite poles.
5. **Decondensation of chromosomes (V)**: This occurs during telophase when the chromosomes begin to uncoil and return to their chromatin state.

### Step 3: Arrange the events in the correct order
Based on the analysis:
1. **DNA Replication (II)** - This is the first event that occurs during the S phase.
2. **Initiation of spindle formation (I)** - This occurs next during prophase.
3. **Disappearance of Golgi complex, E.R, and nuclear membrane (III)** - This also occurs during prophase.
4. **Movement of chromosomes towards the poles (IV)** - This occurs during anaphase.
5. **Decondensation of chromosomes (V)** - This occurs during telophase.

### Final Sequence
The correct sequence of events is:
1. II (DNA replication)
2. I (Initiation of spindle formation)
3. III (Disappearance of Golgi complex, E.R, and nuclear membrane)
4. IV (Movement of chromosomes towards the poles)
5. V (Decondensation of chromosomes)

### Answer
The correct order is: II, I, III, IV, V.