Answer
miRNA, short for microRNA, is a type of small non-coding RNA molecule that regulates gene expression. miRNAs are typically 20-22 nucleotides long and bind to the 3' untranslated region (UTR) of target mRNAs, leading to their degradation or translational inhibition. This process helps control the expression of specific genes and plays a crucial role in various cellular processes, including development, differentiation, and disease.