[Campbell Biology P.429] Which of the following statements correctly differentiates between ... | Practice Question

Which of the following statements correctly differentiates between microRNAs miRNAs , small interfering RNAs siRNAs , and piwi-interacting RNAs piRNAs as described in the text?

  • A: miRNAs are derived from double-stranded precursors, while siRNAs are from single-stranded precursors.
  • B: Both miRNAs and siRNAs regulate gene expression by targeting mRNA, but piRNAs are primarily involved in chromatin remodeling and transposon suppression.
  • C: siRNAs are used by bacteria as a defense system, whereas miRNAs are exclusive to eukaryotes.
  • D: All three types of ncRNAs act by initiating transcription of target genes.

Explanation

miRNAs and siRNAs are both involved in post-transcriptional gene silencing by binding to and regulating mRNA either degradation or translation blockade . piRNAs, on the other hand, are specifically noted for their role in chromatin remodeling and the suppression of parasitic DNA elements transposons in the genome.