You are studying the regulation of a group of genes and have determined that the full activation of transcription of these genes occurs when histone acetyl transferases have made post-translational modifications specifically to which one of the following amino acids?

#Question id: 3782

#Unit 3. Fundamental Processes

In his work with pneumonia-causing bacteria and mice, Griffith found that

#Question id: 1658

#Unit 4. Cell Communication and Cell Signaling

Which of the following statements is TRUE of IgE?

#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: 12152

#Unit 10. Ecological Principles

#Question id: 720

#Unit 1. Molecules and their Interaction Relevant to Biology

How would a homopolymer of alanine be more likely to form an alpha helix in water or in a hydrophobic medium?