Which of the following events takes place during anaphase stage of mitosis
I. Spindle fibres attach to kinetochores of chromosomes
II. Centromeres split and chromatids separate
III. Chromatids move to opposite poles
IV. Nucleolous, Golgi complex and E.R. reform

Options

A. I and II only
B. II and III only
C. III and IV only
D. I and IV only

Answer

To determine which events occur during the anaphase stage of mitosis, we need to analyze each of the provided statements:

1. **Spindle fibres attach to kinetochores of chromosomes**: This event occurs during the metaphase stage of mitosis, not anaphase. Therefore, this statement is incorrect.

2. **Centromeres split and chromatids separate**: This is a key event that occurs during anaphase. The centromeres, which hold the sister chromatids together, split, allowing the chromatids to separate and move towards opposite poles of the cell. This statement is correct.

3. **Chromatids move to opposite poles**: Following the splitting of the centromeres, the separated chromatids are pulled towards opposite poles of the cell by the shortening of the spindle fibers. This statement is also correct.

4. **Nucleolus, Golgi complex, and E.R. reform**: This event occurs during the telophase stage of mitosis, not anaphase. Therefore, this statement is incorrect.

Based on the analysis, the correct statements regarding the events that take place during anaphase are:

- **II. Centromeres split and chromatids separate**
- **III. Chromatids move to opposite poles**

Thus, the correct answer is that statements II and III are true.

### Summary of the Solution:
- **Correct Events in Anaphase**:
- II. Centromeres split and chromatids separate (True)
- III. Chromatids move to opposite poles (True)
- **Incorrect Events in Anaphase**:
- I. Spindle fibres attach to kinetochores of chromosomes (False, occurs in metaphase)
- IV. Nucleolus, Golgi complex, and E.R. reform (False, occurs in telophase)