Assertion: hnRNA is larger than mRNNA.
Reason: hnRNA has no translating introns and more exons than required for translation.

Options

A. If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion.
B. If both Assertion and Reason are true and the Reason is not the correct explanation of the Assertion.
C. If Assertion is true but the Reason is false.
D. If both Assertion and Reasom are false.

Answer

### Step-by-Step Solution:

1. **Understanding hnRNA and mRNA**:
- hnRNA (heteronuclear RNA) is also known as the primary transcript. It is synthesized from DNA during the transcription process.
- mRNA (messenger RNA) is the processed form of hnRNA that is used as a template for translation.

2. **Assertion Analysis**:
- The assertion states that "hnRNA is larger than mRNA." This is true because hnRNA contains both introns and exons, while mRNA only contains exons after splicing. Since introns are removed during the processing of hnRNA to form mRNA, hnRNA is indeed larger.

3. **Reason Analysis**:
- The reason states that "hnRNA has no translating introns and more exons than required for translation." This statement is incorrect.
- hnRNA contains both introns (non-coding regions) and exons (coding regions). During the processing of hnRNA to mRNA, introns are removed, and the exons are spliced together. Therefore, it does not have "more exons than required for translation"; it has the same number of exons as mRNA after processing.

4. **Conclusion**:
- Since the assertion is true (hnRNA is larger than mRNA) and the reason is false (hnRNA does contain introns and does not have more exons than mRNA), the correct answer is that the assertion is true, but the reason is false.

### Final Answer:
- **Assertion is true, Reason is false.**