With respect to microRNAs, which, if any, of the following statements, is FALSE?)

A. MicroRNA genes often occur in gene clusters within introns of protein-coding genes and are usually transcribed by RNA polymerase II.

B. Like an mRNA a miRNA is initially produced as a larger precursor RNA that, like the great majority of mRNAs, usually has a 5’ cap and a poly(A) tail.

C. MicroRNAs are produced by germ-line cells only.

D. A miRNA is initially produced as a duplex RNA but in order to work it needs to be converted into a single-strand RNA.

E. MicroRNAs usually work as transcription factors.

#Question id: 4460

#Unit 3. Fundamental Processes

During initial transcription, the active center of RNA polymerase is translocated forward relative to the DNA template and synthesizes short transcripts before aborting, then repeats this cycle until it escapes the promoter. Three models have been proposed to account for this;

i. Polymerase moves along the DNA.

ii. The front part of the enzyme moves along the DNA, but because of a flexible region within the enzyme, the back part of the enzyme can remain stationary at the promoter.

iii. The enzyme remains stationary and pulls the DNA into itself.

#Question id: 4461

#Unit 3. Fundamental Processes

According to some experiments, during initial transcription, the polymerase remains stationary on the promoter, unwinds downstream DNA, and pulls that DNA into itself, which model is this?

#Question id: 4462

#Unit 3. Fundamental Processes

Promoter escape is associated with the breaking of all interactions (at the given promoter) between;

#Question id: 4463

#Unit 3. Fundamental Processes

___?____ is a way to store and mobilize energy during transcription initiation, and its release upon escape is what enables polymerase to break free of the promoter and dislodge s factor from the core.

#Question id: 4464

#Unit 3. Fundamental Processes

Role of Gre factor;

#Question id: 4465

#Unit 3. Fundamental Processes

Main function of Nus proteins in transcription,