Nucleoprotein complex formation stage is

Options

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

Answer

To solve the question regarding the nucleoprotein complex formation stage, we can follow these steps:

### Step-by-Step Solution:

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

2. **Focus on Meiosis I**:
- Meiosis I is further divided into several phases, particularly Prophase I, which is crucial for the pairing of homologous chromosomes.

3. **Identify the Phases of Prophase I**:
- Prophase I is subdivided into five distinct phases:
- Leptotene
- Zygotene
- Pachytene
- Diplotene
- Diakinesis

4. **Define Nucleoprotein Complex**:
- The term "nucleoprotein complex" refers to the synaptonemal complex, which is essential for the pairing of homologous chromosomes during meiosis.

5. **Determine When the Nucleoprotein Complex Forms**:
- The synaptonemal complex forms during the Zygotene phase of Prophase I. This is when homologous chromosomes begin to pair up, a process known as synapsis.

6. **Analyze the Options**:
- Given the options:
- A) Leptotene
- B) Zygotene
- C) Pachytene
- D) Diplotene
- Since the formation of the nucleoprotein complex occurs during the Zygotene phase, the correct answer is **B) Zygotene**.

### Final Answer:
The nucleoprotein complex formation stage is **Zygotene**.

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