In case of many animal cells the chromosome shows particular arrangement in leptotene stage, in which the ends of chromosomes converge towards the side having replicated centrosomes. This stage is called

Options

A. Bivalent stage
B. Bouqet stage
C. Tetravalent stage
D. Synapsis

Answer

To answer the question regarding the specific arrangement of chromosomes in the leptotene stage of animal cells, we can break down the solution into clear steps:

### Step-by-Step Solution:

1. **Understanding the Leptotene Stage**:
- The leptotene stage is the first stage of prophase I in meiosis. During this stage, chromosomes begin to condense and become visible under a microscope.

2. **Chromosome Arrangement**:
- In many animal cells during the leptotene stage, the ends of the chromosomes converge towards the side where the replicated centrosomes are located. This specific arrangement is crucial for the subsequent stages of meiosis.

3. **Identifying the Stage**:
- The question asks for the name of this particular arrangement of chromosomes in the leptotene stage. The correct term for this arrangement is known as the **Wackert's stage**.

4. **Evaluating Other Options**:
- **Bivalent Stage**: This refers to the pairing of homologous chromosomes, which occurs later in prophase I, not during leptotene.
- **Tetravalent Stage**: This term is not applicable here, as it refers to a situation where four chromatids are involved, typically seen in the context of bivalents.
- **Synapsis**: This is the process of homologous chromosomes pairing up, which also occurs later in prophase I and is not specific to the leptotene stage.

5. **Conclusion**:
- Based on the analysis, the correct answer to the question is **Wackert's stage**.

### Final Answer:
The stage in which the ends of chromosomes converge towards the side having replicated centrosomes in the leptotene stage is called **Wackert's stage**.

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