Which type of mRNA arrangement is found in prokaryotes?

In prokaryotes, the predominant type of mRNA arrangement is polycistronic. This means that a single mRNA molecule can encode multiple proteins. This arrangement allows for the coordinated regulation of genes that are often part of the same metabolic pathway or function together.

In prokaryotic cells, transcription and translation occur simultaneously, and because of this, multiple open reading frames can be present in one mRNA molecule. Each cistron within a polycistronic mRNA typically has its own ribosome binding site, facilitating the translation of each protein by the ribosome. This is particularly efficient for prokaryotic cells, which can rapidly respond to environmental changes by coordinating the synthesis of related proteins needed for specific functions.

In contrast, eukaryotic mRNA is primarily monocistronic, typically encoding only one protein per mRNA transcript, and often undergoes extensive processing before translation. Thus, the polycistronic nature of prokaryotic mRNA reflects a fundamental difference in gene expression strategies between prokaryotes and eukaryotes.