mRNA direct the building of proteins through a sequience of

Options

A. Introns
B. Codons
C. Exons
D. Anticodons

Answer

To answer the question "mRNA directs the building of proteins through a sequence of...", we need to analyze the options provided: intron, codon, axon, and anticodon.

### Step-by-Step Solution:

1. **Understanding mRNA**:
- mRNA (messenger RNA) is a type of RNA that carries genetic information from DNA to the ribosome, where proteins are synthesized.

2. **Identifying the Options**:
- **Intron**: These are non-coding sequences found in pre-mRNA. They are spliced out during RNA processing and are not present in mature mRNA. Hence, they do not play a role in directing protein synthesis.
- **Codon**: A codon is a sequence of three nucleotides in mRNA that corresponds to a specific amino acid or a stop signal during protein synthesis. Codons are crucial as they dictate the sequence of amino acids in a protein.
- **Axon**: This seems to be a typographical error in the context; the correct term should be "exon". Exons are coding sequences that remain in mRNA after splicing and are important for the final mRNA that is translated into protein. However, they do not directly direct the building of proteins; rather, they are part of the mRNA structure.
- **Anticodon**: This is a sequence of three nucleotides in tRNA that is complementary to a codon in mRNA. Anticodons help in the translation process but do not directly direct the building of proteins.

3. **Conclusion**:
- The correct answer is **codon**. Codons in mRNA are the sequences that directly dictate the building of proteins by specifying which amino acids will be added during translation.

### Final Answer:
mRNA directs the building of proteins through a sequence of **codon**.

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