When synapsis is complete all along the chromosomes, the cell is said to have entered a stage called

Options

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

Answer

To answer the question, "When synapsis is complete all along the chromosomes, the cell is said to have entered a stage called," we will follow these steps:

### Step-by-Step Solution:

1. **Understand Synapsis**:
- Synapsis refers to the pairing of homologous chromosomes during meiosis. This is an essential process for genetic recombination and occurs in a specific stage of meiosis.

2. **Identify the Stages of Meiosis**:
- Meiosis consists of several stages, which include prophase I, metaphase I, anaphase I, telophase I, and then meiosis II. Prophase I is further divided into five substages: leptotene, zygotene, pachytene, diplotene, and diakinesis.

3. **Locate the Stage of Synapsis**:
- Synapsis occurs during the zygotene stage of prophase I. This is when homologous chromosomes begin to pair up.

4. **Determine the Next Stage After Synapsis**:
- After synapsis is complete, the cell enters the pachytene stage. During this stage, the chromosomes become thicker and shorter as they condense.

5. **Examine Other Stages**:
- **Diplotene**: This stage follows pachytene and is characterized by the beginning of the unpairing of homologous chromosomes and the formation of chiasmata.
- **Diakinesis**: This is the final stage of prophase I, where chromosomes condense further, the nuclear envelope breaks down, and the nucleolus disappears.

6. **Select the Correct Answer**:
- Since the question asks for the stage when synapsis is complete, the correct answer is **pachytene**.

### Final Answer:
The cell is said to have entered the stage called **pachytene** when synapsis is complete all along the chromosomes.

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