Question

Shine-Dalgarno sequences are present in mRNAs of

A) prokaryotes.
B) eukaryotes.
C) humans.
D) plants.
E) both prokaryotes and eukaryotes.

Answer 1

The Shine-Dalgarno sequence is unique to prokaryotes and is essential for the initiation of translation in these organisms by aligning the mRNA with the ribosomal subunit.

Step-by-step explanation:

The Shine-Dalgarno sequence (AGGAGG) is present in the mRNAs of prokaryotes. Its primary function is to initiate prokaryotic translation by interacting with rRNA molecules that comprise the 30S ribosomal subunit. This interaction ensures that the ribosomes dock at the correct location on the mRNA to start the translation process. This sequence is not found in eukaryotic organisms; instead, they have other mechanisms, such as the Kozak sequence, to initiate translation.