#Question id: 7753
#Unit 5. Developmental Biology
#Question id: 15416
#Unit 5. Developmental Biology
#Question id: 19377
#Unit 12. Applied Biology
#Question id: 57
#Unit 1. Molecules and their Interaction Relevant to Biology
A(n) ________ has charge but negligible mass, whereas a(n) ________ has mass but no charge.
#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.