Ends of chromosomes are attached with nuclear envelope at attachment plate in

Options

A. Leptotene
B. Zygotene
C. Pachytene
D. Diplotene

Answer

To solve the question "Ends of chromosomes are attached with nuclear envelope at attachment plate in," we need to analyze the stages of prophase I of meiosis and identify which stage corresponds to the attachment of chromosome ends to the nuclear envelope.

### Step-by-Step Solution:

1. **Understanding the Stages of Meiosis**:
- Meiosis consists of two rounds of cell division: meiosis I and meiosis II. Prophase I is further divided into several stages: leptotene, zygotene, pachytene, diplotene, and diakinesis.

2. **Identifying the Stages**:
- **Leptotene**: In this initial stage, chromosomes start to condense and become visible. The ends of the chromosomes attach to the nuclear envelope at the attachment plate.
- **Zygotene**: This stage follows leptotene, where homologous chromosomes begin to pair up (synapsis). However, the attachment to the nuclear envelope is not the primary characteristic of this stage.
- **Pachytene**: At this stage, crossing over occurs between homologous chromosomes, but the attachment to the nuclear envelope is not emphasized.
- **Diplotene**: In this stage, synapsis ends, and the chromosomes start to separate, but they remain attached at crossover points.

3. **Conclusion**:
- The correct answer is **leptotene**, as it is the stage where the ends of chromosomes are attached to the nuclear envelope at the attachment plate.

### Final Answer:
The ends of chromosomes are attached with the nuclear envelope at the attachment plate in **leptotene**.