Which is not characteristic of meiosis

Options

A. Two stages of DNA replication, first before meiosis I and second before meiosis II
B. Recombination and crossing over
C. Sister chromatids separate during anaphase II
D. Nuclear membrane disappears towards end of prophase.

Answer

To determine which option is not a characteristic of meiosis, we need to analyze the characteristics of meiosis and the provided options.

### Step-by-Step Solution:

1. **Understand Meiosis**: Meiosis is a specialized form of cell division that reduces the chromosome number by half, resulting in four haploid cells. It consists of two sequential divisions: meiosis I and meiosis II.

2. **Analyze the Options**:
- **Option 1**: Two stages of DNA replication, first before meiosis I and second before meiosis II.
- **Option 2**: Recombination and crossing over.
- **Option 3**: Sister chromatids separate during anaphase II.
- **Option 4**: Nuclear membrane disappears towards the end of prophase.

3. **Evaluate Each Option**:
- **Option 1**: This is incorrect because DNA replication occurs only once before meiosis I. There is no second stage of DNA replication before meiosis II. After meiosis I, there is a short interkinesis phase without DNA replication.
- **Option 2**: This is a characteristic of meiosis as it involves recombination and crossing over during prophase I.
- **Option 3**: This is true; sister chromatids separate during anaphase II of meiosis.
- **Option 4**: This is also true; the nuclear membrane does disappear towards the end of prophase I.

4. **Conclusion**: The option that is not a characteristic of meiosis is **Option 1**: Two stages of DNA replication, first before meiosis I and second before meiosis II.

### Final Answer:
The characteristic that is not true for meiosis is: **Two stages of DNA replication, first before meiosis I and second before meiosis II.**

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