Identify the correct combination regarding anaphase, anaphase I and anaphase II

Options

A. Anaphase - centromere splits, Anaphase I - centromere splits, Anaphase II - centromere splits
B. Anaphase - chromatids move to opposite poles, Anaphase I - homologous chromosomes separate, Anaphase II - centromere splits
C. Anaphase - chromosomes cluster at opposite poles, Anaphase I - homologous chromosomes separate, Anaphase II - centromere splits
D. Anaphase - chromosomes move to one pole, Anaphase I - homologous chromosomes separate, Anaphase II - centromere splits.

Answer

To identify the correct combination regarding anaphase, anaphase I, and anaphase II, we need to understand the key events that occur during these phases of cell division. Here’s a step-by-step breakdown:

### Step 1: Understand Anaphase
- **Anaphase** is a stage in mitosis where sister chromatids are pulled apart towards opposite poles of the cell. This occurs after the centromere splits, allowing the chromatids to separate.

### Step 2: Understand Anaphase I
- **Anaphase I** occurs during meiosis I. In this phase, homologous chromosomes (each consisting of two sister chromatids) are separated and pulled to opposite poles of the cell. Importantly, the centromeres do not split in this phase; the entire homologous chromosomes are moved.

### Step 3: Understand Anaphase II
- **Anaphase II** occurs during meiosis II. Similar to mitosis, this phase involves the splitting of the centromeres of the sister chromatids, allowing them to move towards opposite poles of the cell.

### Step 4: Analyze the Options
- **Option 1**: Anaphase centromere splits - **Correct** (this happens in mitosis)
- **Option 1**: Anaphase I centromere splits - **Incorrect** (centromere remains intact in anaphase I)
- **Option 2**: Anaphase chromatids move to opposite poles - **Correct** (this happens in anaphase of mitosis and anaphase II)
- **Option 2**: Anaphase I homologous chromosomes separate - **Correct** (homologous chromosomes separate in anaphase I)
- **Option 2**: Anaphase II centromere splits - **Correct** (this happens in anaphase II)
- **Option 3**: Anaphase chromosomes cluster at opposite poles - **Incorrect** (chromatids cluster, not whole chromosomes)
- **Option 4**: Anaphase chromosomes move to one pole - **Incorrect** (chromatids move to opposite poles)

### Conclusion
After analyzing the options, the correct combination regarding anaphase, anaphase I, and anaphase II is **Option 2**.