Exons are

Exons are

• A. non-coding regions
• B. coding regions expressed
• C. introns
• D. promoter regions

Answer: (B)

Exons are the parts of a gene that carry the information to make a protein and are retained in the mature mRNA. In eukaryotic genes, transcripts often include both exons and introns. After transcription, the introns are removed and the exons are joined together, producing a final mRNA that is translated into a protein. That’s why exons are described as coding regions expressed—they contain the sequence information that ends up in the protein. By contrast, introns are noncoding and are spliced out, while promoter regions are DNA sequences that help initiate transcription and are not part of the mature, protein-coding mRNA. Non-coding regions can refer to parts of the gene that do not code for protein, such as introns and regulatory elements.

Exons are the parts of a gene that carry the information to make a protein and are retained in the mature mRNA. In eukaryotic genes, transcripts often include both exons and introns. After transcription, the introns are removed and the exons are joined together, producing a final mRNA that is translated into a protein. That’s why exons are described as coding regions expressed—they contain the sequence information that ends up in the protein. By contrast, introns are noncoding and are spliced out, while promoter regions are DNA sequences that help initiate transcription and are not part of the mature, protein-coding mRNA. Non-coding regions can refer to parts of the gene that do not code for protein, such as introns and regulatory elements.