Which of the following correctly arranges the major steps of eukaryotic gene expression in chronological order?

• A. Translation → Transcription → RNA processing → Protein modification
• B. Transcription → Translation → RNA processing → Protein modification
• C. RNA processing → Transcription → Translation → Protein modification
• D. Transcription → RNA processing → Translation → Protein modification

Answer: (D)

Verified step by step guidance

1. Understand the process of eukaryotic gene expression, which involves multiple steps to convert genetic information in DNA into a functional protein.
2. Step 1: Transcription occurs first. During this step, the DNA sequence of a gene is transcribed into messenger RNA (mRNA). This process takes place in the nucleus of eukaryotic cells.
3. Step 2: RNA processing follows transcription. The pre-mRNA undergoes modifications such as the addition of a 5' cap, splicing to remove introns, and the addition of a poly-A tail at the 3' end. This step ensures the mRNA is mature and ready for translation.
4. Step 3: Translation is the next step. The mature mRNA is transported out of the nucleus to the ribosome, where it is translated into a polypeptide chain (protein) using the genetic code.
5. Step 4: Protein modification occurs after translation. The newly synthesized protein may undergo post-translational modifications, such as folding, cleavage, or the addition of functional groups, to become fully functional.