Final answer:
RNA interference (RNAi) is the process by which fruit flies use siRNAs or miRNAs to silence transposase genes and inhibit transposition, either by cleaving the mRNA or inhibiting its translation.
Step-by-step explanation:
The process by which fruit flies use small RNA molecules to silence transposase genes and inhibit transposition is known as RNA interference (RNAi). This biological mechanism involves small interfering RNAs (siRNAs) or microRNAs (miRNAs), which are bound to a protein complex called RNA-induced silencing complex (RISC). When siRNAs are completely complementary to the mRNA, the siRNA-RISC complex binds to the mRNA and cleaves it, thereby preventing the production of transposase enzymes that facilitate transposition. If miRNA is mostly complementary, it can inhibit translation by binding to the mRNA, leading to gene silencing. These small RNAs play a crucial role in defending the organism against potentially harmful transposable elements and viral RNA by targeting their transcripts for destruction or translation inhibition. RNAi is considered a powerful tool in genetic research and has therapeutic potential in treating viral infections by mimicking this natural gene silencing process.