Identify CORRECTLY matched pair.

Options

A. Zygotene -Pairing of homologous chromosomes
B. Pachytene-Disjunction of hi homologous chromosomes
C. Diakinesis-Recombination of non sister chromatids of homologous chromosomes
D. Diplotene-Nucleolus disappears

Answer

To solve the question of identifying the correctly matched pair from the given options, we will analyze each option step by step.

### Step 1: Analyze Option 1 - Zygotene
- **Definition**: Zygotene is the second stage of prophase I in meiosis.
- **Function**: During zygotene, homologous chromosomes begin to pair up and form synapses, which is the process of pairing.
- **Conclusion**: This option is correctly matched as it describes the pairing of homologous chromosomes.

### Step 2: Analyze Option 2 - Pachytene
- **Definition**: Pachytene is the third stage of prophase I in meiosis.
- **Function**: In this stage, the paired homologous chromosomes become shorter and thicker, and crossing over occurs.
- **Conclusion**: The statement that pachytene means disjunction of homologous chromosomes is incorrect. Therefore, this option is not correctly matched.

### Step 3: Analyze Option 3 - Diakinesis
- **Definition**: Diakinesis is the fifth and last stage of prophase I in meiosis.
- **Function**: In this stage, homologous chromosomes are fully separated, and the nuclear envelope breaks down.
- **Conclusion**: The statement that diakinesis involves recombination of non-sister chromatids is incorrect. Thus, this option is not correctly matched.

### Step 4: Analyze Option 4 - Diplotene
- **Definition**: Diplotene is the fourth stage of prophase I in meiosis.
- **Function**: During diplotene, the homologous chromosomes begin to separate but remain connected at points called chiasmata.
- **Conclusion**: The statement that the nucleus disappears during diplotene is incorrect. Therefore, this option is also not correctly matched.

### Final Conclusion
The only correctly matched pair is:
- **Option 1: Zygotene** - Correctly describes the pairing of homologous chromosomes.