In ______________, messenger RNA must be processed before it leaves the ______________.

In ______________, messenger RNA must be processed before it leaves the ______________.

• A. Prokaryotes; cytoplasm
• B. Eukaryotes; nucleus
• C. Bacteria; nucleus
• D. Archaea; cytoplasm

Answer: (B)

In this context, the important idea is that mRNA processing happens in eukaryotes before the message can exit the nucleus. In eukaryotic cells, transcription occurs inside the nucleus and the initial RNA transcript (pre-mRNA) is modified through capping, splicing to remove introns, and adding a poly-A tail. These processing steps are essential before the mature mRNA is exported through the nuclear envelope to the cytoplasm, where it will be translated. In contrast, prokaryotes and archaea lack a nucleus and typically do not perform this kind of RNA processing before mRNA is used, so the idea of leaving the nucleus doesn’t apply. Thus, the statement correctly describes eukaryotic gene expression.

In this context, the important idea is that mRNA processing happens in eukaryotes before the message can exit the nucleus. In eukaryotic cells, transcription occurs inside the nucleus and the initial RNA transcript (pre-mRNA) is modified through capping, splicing to remove introns, and adding a poly-A tail. These processing steps are essential before the mature mRNA is exported through the nuclear envelope to the cytoplasm, where it will be translated. In contrast, prokaryotes and archaea lack a nucleus and typically do not perform this kind of RNA processing before mRNA is used, so the idea of leaving the nucleus doesn’t apply. Thus, the statement correctly describes eukaryotic gene expression.