If a problem with RNA interference is caused by a failure of the target mRNA to be cleaved and degraded, but all other steps in the process proceed as normal, this is likely the result of a problem in which of the following components?

(A) Guide strand
(B) Argonaute
(C) shRNA
(D) Dicer

D- Dicer

Explanation:

Dicer, also known as endoribonuclease Dicer or helicase with RNase motif, is an enzyme that in humans is encoded by the DICER1 gene. Being part of the RNase III family, Dicer cleaves double-stranded RNA (dsRNA) and pre-microRNA (pre-miRNA) into short double-stranded RNA fragments called small interfering RNA and microRNA, respectively. These fragments are approximately 20-25 base pairs long with a two-base overhang on the 5' ends. Dicer facilitates the activation of the RNA-induced silencing complex (RISC), which is essential for RNA interference. RISC has a catalytic component Argonaute, which is an endonuclease capable of degrading messenger RNA (mRNA).

(B) Argonaute

Explanation:

Dicer is a helicase enzyme with a proper RNA motif and encodes ownself by utilizing DICER1 gene. In dsDNA, RISC is activated by the help of dicer enzyme and it also regulated the process. RISC has a catalytic component Argonaute, which is an endonuclease capable of degrading messenger RNA (mRNA). When this endonuclease malfunctions, the mRNA no longer be degraded and this failure leads to improper protein translation.