Question

Why do cells use microrna to break down mrna instead of not transcribing it in the first place?

Answer 1

Cells use microRNA (miRNA) to break down mRNA instead of not transcribing it in the first place because miRNAs provide a means of post-transcriptional regulation.

Step-by-step explanation:

Cells use microRNA (miRNA) to break down mRNA instead of not transcribing it in the first place because miRNAs provide a means of post-transcriptional regulation. miRNAs target unwanted mRNAs for degradation, allowing cells to control gene expression after the transcription of mRNA has already occurred. When miRNA molecules bind to the 3' untranslated region (UTR) of the mRNA, they recruit proteins that lead to mRNA degradation, preventing the translation of the mRNA into protein.