In eukaryotes, mRNA containing genetic code is formed by

Options

A. Transcription from split genes
B. Transcription from hn RNA
C. RNA splicing from hn RNA
D. RNA splicing from DNA

Answer

To solve the question "In eukaryotes, mRNA containing genetic code is formed by," we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks how mRNA (messenger RNA) is formed in eukaryotic cells, specifically focusing on the process that leads to the formation of mRNA containing genetic code.

2. **Identifying Key Terms**:
- Eukaryotes: Organisms whose cells have a nucleus.
- mRNA: A type of RNA that carries the genetic information from DNA to the ribosome for protein synthesis.
- Genetic Code: The set of rules by which information encoded in mRNA is translated into proteins.

3. **Processes Involved in mRNA Formation**: In eukaryotes, the formation of mRNA involves several processes:
- **Transcription**: The process where DNA is transcribed to form precursor mRNA (pre-mRNA).
- **RNA Splicing**: The process where introns (non-coding regions) are removed from the pre-mRNA, and exons (coding regions) are joined together to form mature mRNA.

4. **Identifying the Correct Process**: The question specifically asks for the process that leads to the formation of mRNA containing genetic code.
- While transcription is the initial step, the question emphasizes the final form of mRNA that is functional and ready for translation, which is achieved through RNA splicing.

5. **Choosing the Correct Option**: Among the options provided:
- **Transcription from split genes**: This is not specific to mRNA formation.
- **Transcription from hnRNA**: hnRNA (heterogeneous nuclear RNA) is a precursor to mRNA but does not directly answer the question.
- **RNA splicing from hnRNA**: This is the correct answer as it describes the process that transforms hnRNA into mature mRNA.
- **RNA splicing from DNA**: This is incorrect as RNA splicing does not occur directly from DNA.

6. **Final Answer**: The correct answer is **RNA splicing from hnRNA**.