Homologous chromosomes shows maximum attraction during :-

Options

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

Answer

To determine when homologous chromosomes show maximum attraction, we need to analyze the stages of meiosis, particularly focusing on prophase I. Here’s a step-by-step breakdown of the solution:

### Step-by-Step Solution:

1. **Understanding Homologous Chromosomes**: Homologous chromosomes are pairs of chromosomes that have the same structure and gene sequence, one inherited from each parent. They are crucial during meiosis for genetic recombination.

2. **Identifying Stages of Meiosis**: Meiosis consists of several stages, particularly during prophase I, which can be subdivided into five stages: leptotene, zygotene, pachytene, diplotene, and diakinesis.

3. **Analyzing Each Stage**:
- **Leptotene**: In this stage, chromosomes start to condense, but homologous chromosomes do not yet show significant attraction.
- **Zygotene**: Here, homologous chromosomes begin to pair up (synapsis) and form the synaptonemal complex. While there is some attraction, it is not at its maximum.
- **Pachytene**: This is the stage where crossing over occurs between non-sister chromatids of homologous chromosomes. This process involves the exchange of genetic material and represents the maximum attraction between homologous chromosomes.
- **Diplotene**: In this stage, the synaptonemal complex begins to disassemble, and the homologous chromosomes start to separate, leading to reduced attraction.
- **Diakinesis**: This is the final stage of prophase I where chromosomes condense further and prepare for metaphase, but the attraction is not at its peak.

4. **Conclusion**: Based on the analysis, the stage where homologous chromosomes show maximum attraction is during **pachytene**.

### Final Answer:
Homologous chromosomes show maximum attraction during **pachytene**.