Question

Prokaryotes commonly use attenuation as a mechanism to control gene expression, but eukaryotes do not. Why do you think that attenuation is more common in prokaryotes than eukaryotes?

Answer 1

Attenuation is a mechanism of regulation of gene expression in prokaryotes. Attenuation involves formation of hairloop stem structure in mRNA which stops transcription (and translation).

It can take place only when transcription and translation are taking place simultaneously. In prokaryotes transcription and translation take place at the same time.

But in eukaryotes, transcription and translation take place at different locations and time.

In short, attenuation is not seen in eukaryotes because transcription and translation do not take place together in eukaryotes, unlike prokaryotes. This is because in prokaryotes transcript contains only coding region but in eukaryotes transcription contains introns (non coding) and exons (coding) region.