Synnaptonemal complex is characteristic of :-

Options

A. Mitotic chromosomes
B. Leptotene chromosomes
C. Paired meiotic chromosomes
D. Metaphase

Answer

To determine the characteristic of the synaptonemal complex, let's analyze the options step by step:

### Step 1: Understanding the Synaptonemal Complex
The synaptonemal complex is a protein structure that forms between homologous chromosomes during meiosis. It plays a crucial role in the process of synapsis, where homologous chromosomes pair up.

### Step 2: Analyzing the Options
1. **Mitotic Chromosomes**: During mitosis, chromosomes do not undergo pairing into homologous chromosomes. Therefore, there is no synaptonemal complex formation in mitotic chromosomes.

2. **Leptotene Chromosomes**: This is the first stage of prophase 1 in meiosis. At this stage, chromosomes begin to condense, but pairing has not yet started. Thus, there is no synaptonemal complex present.

3. **Paired Meiotic Chromosomes**: This refers to homologous chromosomes that have paired during meiosis. The synaptonemal complex forms during the pachytene stage of prophase 1 of meiosis 1, where the homologous chromosomes are closely associated. Therefore, this option is likely correct.

4. **Metaphase**: This term generally refers to a stage in mitosis (unless specified as metaphase 1 or 2 in meiosis). In metaphase, chromosomes are aligned at the cell's equator, and there is no pairing of homologous chromosomes, hence no synaptonemal complex.

### Step 3: Conclusion
Based on the analysis:
- The synaptonemal complex is characteristic of **paired meiotic chromosomes** (Option 3).

### Final Answer
**Option 3: Paired meiotic chromosomes** is the correct answer.

---