18. rnai is a technique that silences genes by targeting them and degrading their mrna. how can this technique be used in scientific laboratories? a. rnai is observed in nature, but it can't be used in laboratories. b. rnai allows scientists to turn off one gene specifically to study its effect. c. rnai has been used in laboratories to make bacteria more susceptible to antibiotics, but has limited application in eukaryotic cells. d. rnai is a powerful tool for degrading mrna, but because it doesn't degrade other types of rna, its use is limited.