Question

RNA interference (RNAi) is a mechanism of gene silencing that is mediated by the presence of double-stranded?

1) RNA molecules
2) DNA molecules
3) Protein molecules
4) Lipid molecules

Answer 1

RNA interference (RNAi) is a biological process for gene silencing mediated by double-stranded RNA molecules, involving siRNAs or miRNAs that are processed by DICER and incorporated into RISC to target mRNA.

Step-by-step explanation:

The mechanism of RNA interference (RNAi) is a form of gene silencing that is mediated by the presence of double-stranded RNA molecules. In the RNAi process, small interfering RNAs (siRNAs) or microRNAs (miRNAs) play a crucial role. These RNA molecules are bound by enzymes like DICER, which cleave the molecules into short fragments. Then, one strand is incorporated into the RNA-induced silencing complex (RISC) which binds to and cleaves target mRNA if it's a perfect match, or inhibits translation if the miRNA is not perfectly complementary to the mRNA. RNAi is a powerful tool utilized by eukaryotic cells both as a natural defense mechanism against viral invasion and in laboratory research for gene knockdown experiments.