The synaptonemal complex appears:-

Options

A. Between homologous chromosomes
B. In zygotene stage
C. Composed of DNA + protein
D. All of these

Answer

To answer the question "The synaptonemal complex appears:", we need to analyze the characteristics and context of the synaptonemal complex in the cell cycle, particularly during meiosis.

### Step-by-Step Solution:

1. **Understanding the Synaptonemal Complex**:
- The synaptonemal complex is a protein structure that forms between homologous chromosomes during meiosis. It facilitates the pairing of homologous chromosomes and is crucial for the process of genetic recombination.

2. **Stage of Formation**:
- The synaptonemal complex appears during the **zygotene stage** of prophase I in meiosis. During this stage, homologous chromosomes begin to pair up closely, and the synaptonemal complex forms between them.

3. **Composition**:
- The synaptonemal complex is composed of **DNA and proteins**. It consists of lateral elements that are formed by the chromatin of homologous chromosomes and a central element that connects these lateral elements.

4. **Conclusion**:
- Given the options provided, the correct answer is **"all of these"** because:
- The synaptonemal complex appears during the zygotene stage.
- It is composed of DNA and proteins.
- Therefore, all statements regarding the synaptonemal complex are correct.

### Final Answer:
The synaptonemal complex appears during the zygotene stage of meiosis and is composed of DNA and proteins. Thus, the correct answer is **"all of these."**