Final answer:
Operons occur in both prokaryotes and eukaryotes. Prokaryotes have operons, which are clusters of genes that are transcribed together under the control of a single promoter. Eukaryotes do not have operons in the same way, but they have gene clusters that function similarly.
Step-by-step explanation:
Operons occur in both prokaryotes and eukaryotes.
Prokaryotes have operons, which are clusters of genes that are transcribed together under the control of a single promoter. This allows for the coordinated regulation of gene expression. For example, the lac operon in E. coli contains three structural genes involved in lactose metabolism.
Eukaryotes, on the other hand, do not have operons in the same way as prokaryotes. However, they have gene clusters that function similarly to operons, and many of the principles of gene regulation learned from prokaryotes can be applied to eukaryotes.