Which of these is not a key feature of meiosis

Options

A. Meiosis involves two sequential cycles of nuclear and cell division
B. Meiosis involves pairing of homologous chromosomes
C. Two cycles of DNA replication occur during meiosis
D. There is recombination between the paired homologous chromosomes

Answer

To determine which of the options is not a key feature of meiosis, we will analyze each option step by step.

### Step-by-Step Solution:

1. **Understanding Meiosis**: Meiosis is a type of cell division that reduces the chromosome number by half, resulting in four haploid cells. It consists of two sequential stages: Meiosis I and Meiosis II.

2. **Analyzing Option 1**: "Meiosis involves two sequential cycles of nuclear and cell division."
- This statement is true. Meiosis consists of two main stages, Meiosis I and Meiosis II, which involve nuclear and cell division.

3. **Analyzing Option 2**: "Meiosis involves pairing of homologous chromosomes."
- This statement is also true. During Meiosis I, homologous chromosomes pair up, which is essential for the process of recombination.

4. **Analyzing Option 3**: "Two cycles of DNA replication occur during meiosis."
- This statement is false. DNA replication occurs only once before Meiosis I, not twice. Therefore, this option is not a key feature of meiosis.

5. **Analyzing Option 4**: "There is a recombination between the paired homologous chromosomes."
- This statement is true. Recombination, or crossing over, occurs during Meiosis I when homologous chromosomes exchange genetic material.

6. **Conclusion**: Based on the analysis, the option that is not a key feature of meiosis is Option 3: "Two cycles of DNA replication occur during meiosis."

### Final Answer:
The correct answer is **Option 3**.

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