Tetrads of chromatids are more clearly visible in

Options

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

Answer

To solve the question "Tetrads of chromatids are more clearly visible in," we need to analyze the stages of meiosis where tetrads can be observed. Here's a step-by-step breakdown of the solution:

### Step 1: Understand the term "tetrads"
Tetrads refer to a group of four chromatids formed during meiosis. They consist of two homologous chromosomes, each made up of two sister chromatids.

### Step 2: Identify the stages of meiosis
Meiosis consists of several stages, particularly in prophase I, where the tetrads are formed. The stages include:
- Leptotene
- Zygotene
- Pachytene
- Diplotene

### Step 3: Analyze each option
1. **Leptotene**: In this stage, chromosomes begin to condense, but tetrads are not yet formed. Thus, tetrads are not clearly visible here.

2. **Zygotene**: This stage is characterized by the pairing of homologous chromosomes, but the tetrads are not fully formed and visible yet.

3. **Pachytene**: This is the stage where the tetrads are clearly visible. It is during this stage that crossing over occurs between homologous chromosomes, and the structure of the tetrads can be observed.

4. **Diplotene**: In this stage, the synaptonemal complex begins to disappear, and while tetrads can still be seen, they are not as clearly visible as in the Pachytene stage.

### Step 4: Conclusion
Based on the analysis, the correct answer is **Pachytene**, where tetrads of chromatids are most clearly visible.

### Final Answer:
Tetrads of chromatids are more clearly visible in **Pachytene**.

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