Answer :
RNA interference (RNAi) is an important biological process in which RNA molecules inhibit gene expression or translation by neutralizing targeted mRNA molecules. This process is primarily mediated by small RNA molecules.
Among the options provided, the RNA molecule that mediates RNA interference is microRNA (miRNA).
microRNA (miRNA) is:
Small in Size: These are short RNA molecules, usually 21-25 nucleotides long.
Derived from Endogenous Genes: miRNAs are encoded by the genome of the organism and are initially transcribed as longer precursors called pri-miRNAs.
Processed to Form Active Structures: These pri-miRNAs are processed in two key steps. First, they are cleaved in the nucleus to form precursor miRNA (pre-miRNA), then exported to the cytoplasm where they are further processed by the enzyme Dicer into mature miRNA.
Function in Gene Regulation: The mature miRNAs are incorporated into a complex known as the RNA-induced silencing complex (RISC). Within this complex, miRNAs guide the RISC to complementary mRNA targets, leading to repression of gene expression either by degrading the target mRNA or by inhibiting its translation.
In summary, microRNA plays a crucial role in regulating gene expression by binding to target mRNA molecules and preventing their translation into proteins. Understanding RNA interference and miRNA is essential in biotechnology and medicine, as they hold potential for developing therapeutic strategies for various diseases.
