The meiotic stage where synapsis takes place is:

Options

A. leptotene
B. zygotene
C. pachytene
D. diplotene

Answer

To determine the meiotic stage where synapsis occurs, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Process of Synapsis**:
- Synapsis is the process where homologous chromosomes pair up during meiosis. This is crucial for genetic recombination and proper segregation of chromosomes.

2. **Identify the Stages of Meiosis**:
- Meiosis consists of two main divisions: Meiosis I and Meiosis II. Meiosis I has several phases, including Prophase I, which is further divided into sub-stages.

3. **Focus on Prophase I**:
- Prophase I is the stage where synapsis occurs. It has five sub-stages: Leptotene, Zygotene, Pachytene, Diplotene, and Diakinesis.

4. **Analyze Each Sub-stage**:
- **Leptotene**: This is the first sub-stage of Prophase I where chromosomes start to condense but homologous chromosomes have not yet paired.
- **Zygotene**: This is the stage where synapsis begins. Homologous chromosomes start to align and pair up.
- **Pachytene**: This stage follows Zygotene where the chromosomes are fully paired, and crossing over may occur.
- **Diplotene**: In this stage, the homologous chromosomes begin to separate but are still connected at chiasmata.

5. **Conclusion**:
- Since synapsis specifically occurs during the Zygotene stage, the correct answer to the question is **B. Zygotene**.

### Final Answer:
The meiotic stage where synapsis takes place is **B. Zygotene**.