#Question id: 794
#Unit 1. Molecules and their Interaction Relevant to Biology
A single-stranded DNA molecule contains 40 nucleotides with equal amounts of A, C, G, and T. This DNA strand can combine with a complementary DNA strand to form a double-stranded DNA molecule. Which structural feature is found in the single-stranded DNA molecule?
#Question id: 795
#Unit 1. Molecules and their Interaction Relevant to Biology
A single-stranded DNA molecule contains 40 nucleotides and has the sequence 5’-(GA)20-3’. When this single strand binds to a complementary DNA strand,
#Question id: 796
#Unit 1. Molecules and their Interaction Relevant to Biology
Which statement best describes the distinction between the purposes of the two RNAi pathways within the eukaryotic cell?
#Question id: 797
#Unit 1. Molecules and their Interaction Relevant to Biology
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: 798
#Unit 1. Molecules and their Interaction Relevant to Biology
Match the structural properties of DNA with the respective types of DNA in which they are found.
COLUMN – I COLUMN – II
A. Pitch per turn of helix 1. 45.6 angstrom
2. 24.6 angstrom
3. 33.2 angstrom
B. Helix packing diameter 1. 23.7 angstrom
2. 18.4 angstrom
3. 25.5 angstrom
C. Major-groove proportions 1. Flattened out on helix surface
2. Extremely narrow but very deep
3. Wide and of intermediate depth
D. Minor-groove proportions 1. Very broad but shallow
2. Extremely narrow but very deep
3. Narrow and of intermediate depth
#Question id: 799
#Unit 1. Molecules and their Interaction Relevant to Biology
The two cleavage reactions required to generate the miRNA from these primary transcripts are mediated by two distinct RNases. A characteristic of both these enzymes is that they recognize and cleave RNAs on the basis of the structure of their substrates rather than their specific sequence. Which of the following statement is INCORRECT regarding the cleavage reactions that produces a mature RNA?