miRNAs can control gene expression by what action? A. degrading proteins as soon as they are formedB. inhibiting the catalytic activity of rRNAC. binding to mRNAs and degrading them or blocking their translationD. binding to DNA and preventing transcription of certain genesE. seeking out viral DNA and destroying it

C) binding to mRNAs and degrading them or blocking their translation

Explanation:

miRNAs:

miRNAs is the abbreviation of MicroRNAs. These are the small noncoding RNAs of ∼22 nucleotides which can not code for peptides. miRNAs are responsible for gene expression regulation at the level of post transcription. They can do so by forming complementary base pairing with target mRNA and inhibiting their translation.

They silenced mRNA by the following processes:

(1) Cleavage of the mRNA strand into pieces,

(2) stopping mRNA from translation into proteins by ribosomes.

(3) Shortening of mRNA poly (A) tail and destabilizing it.