Assertion :- Zygotene is charactersed by formation of synaptonemal complex .
Reason :- Synoptonemal complex helps in synapsis of non homologous chromosomes.

Options

A. If both Assertion & Reason are True & the Reason is a correct explanation of the Assertion.
B. If both Assertion & Reason are True but Reason is not a correct explanation of the Assertion.
C. If Assertion is True but the Reason is False.
D. If both Assertion & Reason are false.

Answer

To analyze the given assertion and reason, we will break down the statements step by step.

### Step 1: Understand the Assertion
The assertion states that "Zygotene is characterized by the formation of the synaptonemal complex."
- **Explanation**: Zygotene is indeed a stage in prophase I of meiosis where homologous chromosomes begin to pair up and form a structure known as the synaptonemal complex. This complex facilitates the pairing of homologous chromosomes.

### Step 2: Understand the Reason
The reason states that "Synaptonemal complex helps in synapsis of non-homologous chromosomes."
- **Explanation**: This statement is incorrect. The synaptonemal complex is specifically involved in the synapsis of homologous chromosomes, not non-homologous ones. Non-homologous chromosomes do not pair during this phase.

### Step 3: Evaluate the Relationship Between Assertion and Reason
Now, we need to evaluate whether the reason correctly explains the assertion.
- Since the assertion is true (the formation of the synaptonemal complex does occur during zygotene), but the reason is false (the synaptonemal complex does not help in synapsis of non-homologous chromosomes), we conclude that the assertion is true while the reason is false.

### Conclusion
Based on the evaluation:
- The correct answer is that the assertion is true, but the reason is false.

### Final Answer
The assertion is true, and the reason is false.

---