Which of the following is unique to mitosis and not a part of meiosis

Options

A. Homologous chromosomes cross over
B. Homologous chromosomes pair and form bivalents
C. Homologous chromosomes behave independently
D. Chromatids are separated during anaphase.

Answer

To determine which of the following options is unique to mitosis and not a part of meiosis, we will analyze each option provided in the question:

1. **Homologous chromosomes crossover**:
- In both mitosis and meiosis, crossing over can occur. However, crossing over is a specific feature of meiosis, particularly during prophase I when homologous chromosomes exchange genetic material. Therefore, this option is **incorrect**.

2. **Homologous chromosomes pair and form bivalents**:
- This process occurs during meiosis, specifically in prophase I, where homologous chromosomes align and form pairs known as bivalents. This does not happen in mitosis, making this option **incorrect** as well.

3. **Homologous chromosomes behave independently**:
- In mitosis, the chromosomes are duplicated and then separated into two daughter cells, maintaining the same chromosome number. In contrast, meiosis involves two rounds of division, resulting in four cells with half the chromosome number. Therefore, the behavior of homologous chromosomes being independent is a characteristic of mitosis and is **correct**.

4. **Chromatids are separated during anaphase**:
- This occurs in both mitosis and meiosis. In mitosis, sister chromatids are separated during anaphase. In meiosis, chromatids are also separated during anaphase II. Thus, this option is **incorrect**.

Based on the analysis, the correct answer is:
**Homologous chromosomes behave independently** (Option 3).