Which of the following does (do) not require a DNA helicase activity?

a. SWI/SNF function  b. Pol II open-complex formation

c. transcription-factor binding to DNA

d. deacetylation of histone tails

#Question id: 805

#Unit 1. Molecules and their Interaction Relevant to Biology

miRNAs are encoded in the genome as segments of longer transcripts. Their characteristic structure helps identify them and predict the target genes they might regulate. Which of the following are the characteristic features of these small RNA molecules?

I. The functional form of an miRNA is typically 21 or 22 nucleotides (it can vary from 19 to 25 nucleotides).

II. The first cleavage liberates the stem-loop, called the pre-miRNA; the second generates the mature miRNA from the pre-miRNA.

III. The pre-miRNAs can be encoded by any part of a transcript: that is, they might fall within coding regions, within leader regions, or within Introns.

IV. The base pairing between miRNA and target RNA is initiated by interactions of so-called seed residues—the sequence between bases 2 and 9 of the 22-nucleotide miRNA.

#Question id: 24257

#Unit 2. Cellular Organization

#Question id: 11409

#Unit 10. Ecological Principles

Species characteristics that make them less prone to extinction are listed below:

A. Narrow niche and specialized

B. High dispersal power

C. High trophic status

D. Long life span

Which of the following is the correct combination?

#Question id: 674

#Unit 1. Molecules and their Interaction Relevant to Biology

Proline is not often found in a-helices of proteins because it

#Question id: 3841

#Unit 3. Fundamental Processes

The DNA replication occurs in a semi-conservative manner which means