Name the stage of cell cycle at which one of the following events occur:
(i) Chromosomes are moved to spindle equator
(ii) Centromere splits and chromatids separate
(iii) Pairing between homologous chromosomes takes place
(iv) Crossing over between homologous chromosomes takes place

Options

A. Anaphase, Metaphase, Zygotene, Pachytene
B. Metaphase, Pachytene, Zygotene, Diplotene
C. Metaphase, Anaphase, Zygotene, Pachytene
D. Anaphase, Metaphase, Pachytene, Zygotene.

Answer

To answer the question regarding the stages of the cell cycle at which specific events occur, we will analyze each event and identify the corresponding stage.

### Step-by-Step Solution:

1. **Identify the Event: Chromosomes are moved to spindle equator.**
- This event occurs during **Metaphase**. In this stage, chromosomes align at the metaphase plate (the equatorial plane of the cell) due to the action of spindle fibers.

2. **Identify the Event: Centromere splits and chromatids separate.**
- This event occurs during **Anaphase**. In this stage, the centromeres that hold sister chromatids together split, allowing the chromatids to move toward opposite poles of the cell.

3. **Identify the Event: Pairing between homologous chromosomes takes place.**
- This event occurs during **Zygotene**, which is a sub-stage of Prophase I in meiosis. During Zygotene, homologous chromosomes begin to pair up, forming bivalents.

4. **Identify the Event: Crossing over between homologous chromosomes takes place.**
- This event occurs during **Pachytene**, which is another sub-stage of Prophase I in meiosis. In Pachytene, crossing over occurs, where segments of DNA are exchanged between homologous chromosomes, increasing genetic diversity.

### Summary of Answers:
- (i) Metaphase
- (ii) Anaphase
- (iii) Zygotene
- (iv) Pachytene