#Question id: 4075
#Unit 3. Fundamental Processes
Pre-mRNA molecules
a. exist as free RNA molecules in eukaryotic cells.
b. are associated with an abundant set of nuclear proteins.
c. are mostly located in the cytoplasm.
d. are located in the nucleus.
#Question id: 4076
#Unit 3. Fundamental Processes
RNA-binding proteins
a. can be identified by chromatography of UV irradiated nuclear extracts over oligo-dT columns.
b. can be identified by sequence homology to known RNA-binding domains.
c. have a conserved structure as seen by X-ray crystallographic analysis.
d. alter the secondary structure of pre-mRNAs, which decreases interactions with other RNAs or proteins.
e. always remain in the nucleus.
#Question id: 4077
#Unit 3. Fundamental Processes
Which of the following is (are) associated with most polyadenylation events?
a. cleavage of the 5ยด end of the RNA molecule
b. an assembly of a large, multiprotein complex
c. the AAUAAA site upstream of where polyadenylation will occur
d. a GU-rich or U-rich region near the cleavage site
e. slow addition of A residues followed by rapid addition of 200 to 250 more A residues
#Question id: 4078
#Unit 3. Fundamental Processes
Which of the following is (are) required for splicing to occur?
a. two transesterification reactions
b. intact, naturally occurring introns
c. formation of a lariat like structure
d. a branch-point G residue
#Question id: 4079
#Unit 3. Fundamental Processes
What is the evidence that pre-mRNAs are not synthesized unless machinery for processing is properly positioned?
#Question id: 4080
#Unit 3. Fundamental Processes
How the location of exons and introns within a gene are determined?