[Campbell Biology P.429] Which of the following statements accurately describes the function... | Practice Question

Which of the following statements accurately describes the function of microRNAs miRNAs in gene expression regulation?

  • A: They directly transcribe DNA into mRNA.
  • B: They always lead to the degradation of target mRNA molecules.
  • C: They bind to complementary sequences on mRNA, leading to either degradation or translation blockade.
  • D: They are double-stranded RNA molecules that initiate gene transcription.

Explanation

MicroRNAs miRNAs are small, single-stranded RNA molecules that bind to complementary sequences on target mRNA molecules. This binding leads to either the degradation of the mRNA or the blockade of its translation into protein. The outcome depends on the degree of complementarity between the miRNA and the mRNA.