Biology 3130
Molecular Biology II
Final Exam
June 2, 2009
1
Multiple choice:
Not shown
Short answer questions. Limit your answers to ½ page or less. Pictures that clearly convey
meaning and/or point-form are OK! (5 marks each).
1. Draw a diagram illustrating the steps of splicing, beginning with an unprocessed RNA with
two exons flanking a single intron. Identify important features and intermediates. You do not
need to include snRNP complexes in this diagram.
2. What snRNP besides U1 and U5 must bind near the 5’-exon-intron boundary in order for
splicing to occur? Present two kinds of cross-linking experiments to support this conclusion.
3. Draw a diagram of the polyadenylation process, beginning with an RNA that is being
elongated past the polyadenylation site.
4. Design and give sample results of an experiment that demonstrates the cooperativity (or lack
thereof) between CPSF, PAB II, PAP and the poly(A) signal in the polyadenylation of a
substrate.
Long answer questions. Limit your answer to 1 page or less. (10 marks each).
1. You are studying a grave human disease called -thalassemia in which no -globin protein is
produced. You find that the -globin gene’s coding region in people with the disease is normal,
but the mRNA is over a hundred nucleotides longer than normal. You sequence the -globin
gene in these people and find a single base change within the gene’s first intron. Present a
hypothesis to explain the absence of -globin in these patients. What experiments could you
perform to test your hypothesis?
2. Genomic DNA was treated with DNase I for a short period of time. Protein was removed from
the DNA, followed by digestion with BamHI. Southern blotting was performed with probes A, B
and C directed against regions of the gene below. BamHI cut sites are shown on the gene map
where indicated.
(a). Indicate the size in Kbp for each BamHI digestion product in the absence of DNase I
treatment (2 mark).
(b). Indicate the position(s) of nucleosome free region(s), and their distance from each BamHI
cut site. (2 marks)
2
BamHI
A
B
Probe: A
DNase I -
MW (Kbp)
Probe:
TATA
B
-
C
-
14.0
13.0
12.0
3.0
2.0
3
A
+
B
+
C
+
C