Question

This short RNA (miRNA) is found in eukaryotic cells. miRNAs are post-transcriptional regulators that bind to complementary sequences on target mRNAs, resulting in enhancement of mRNA degradation by nucleases and/or _________. For the study of gene functions, artificial introduction of miRNA (siRNA) is performed to cells or animals. This experimental technique is called gene silencing and or _________, compared to the gene-deleting transgenic techniques.

Select one:

a. transcriptional repression ;;;; Knock-Down

b. translational repression ;;;; Knock-Down

c. transcriptional repression ;;;; Knock-Out

d. translational repression ;;;; Knock-Out

e. None of these

Answer 1

deleting a gene from the genome such that no functional product is produced in the cell is called knock out mutation.

miRNA binds to the complementary mRNA and results in mRNA degradation, so miRNA prevents translation of the mRNA.

miRNA decreases the expression of the gene, by degrading or preventing the translation of the gene, so miRNA causes knock down mutation. ( expression of the gene is decreased not completely removed)

so thw answerion b) translation repression;;;; Knock down.