The transcription and transiation can be coupled in _________.

Answer

**Step-by-Step Solution:**

1. **Understanding Transcription and Translation**: Transcription is the process where DNA is converted into mRNA, while translation is the process where mRNA is used to synthesize proteins.

2. **Coupling of Transcription and Translation**: In some organisms, these two processes can occur simultaneously. This is referred to as coupled transcription and translation.

3. **Identifying Organisms**: Coupled transcription and translation is primarily observed in prokaryotes. In prokaryotic cells, there is no compartmentalization; thus, as soon as mRNA is synthesized, ribosomes can attach and begin translation even before transcription is completed.

4. **Eukaryotic Cells**: In contrast, eukaryotic cells have a nucleus where transcription occurs. The mRNA must undergo several modifications (like capping, polyadenylation, and splicing) before it can be translated. This separation in space and time prevents coupling of these two processes in eukaryotes.

5. **Conclusion**: Therefore, the answer to the question is that transcription and translation can be coupled in **prokaryotes**.

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