Which accurately describes the usual process of eukaryotic transcription?

• A. Exons are not transcribed.
• B. Introns are not transcribed.
• C. Both introns and exons are transcribed, but neither type of transcribed region leaves the nucleus.
• D. Both introns and exons are transcribed, but the RNA transcribed from introns does not leave the nucleus.

Answer: (D)

Verified step by step guidance

1. Understand the structure of eukaryotic genes: Eukaryotic genes consist of exons, which are coding regions, and introns, which are non-coding regions.
2. Learn about the transcription process: During transcription, both exons and introns are transcribed into a single RNA molecule called pre-mRNA.
3. Explore RNA processing: The pre-mRNA undergoes processing where introns are removed, and exons are spliced together to form mature mRNA.
4. Recognize the fate of mature mRNA: The mature mRNA, which contains only exons, exits the nucleus and is translated into protein in the cytoplasm.
5. Clarify the role of introns: The RNA transcribed from introns is removed during RNA processing and does not leave the nucleus.