1. Why is DNA more stable than RNA?
2. What would happen if we put DNA duplex into pure distilled water?
3. Why is thymine used in DNA instead of uracil?
4. The whole E. coli genome is about 4.6 Mbp. How many copies of it
are in 1 micro gram
of DNA sample?
5. Promoter is the region located at the 5' end of genes. It is
recognized by RNA
polymerases and the recognition is the most important step for the
initiation of gene
expression. If we assume there are one thousand promoters with an
identical sequence in E.
coli genome, what should be the minimum length of this promoter
sequence, assuming that
RNA polymerases recognize bases as we read alphabets?
6. What is the average size of the DNA fragments that are obtained
from the full digestion
by 2 different restriction enzymes in a single reaction mixture, in
which one is 6 base and
the other one is 4 base recognition?
7. The communication of information in life is done by the
complementarity of molecules.
Protein sequence is determined by mRNA sequence, which is in turn
copied from DNA
sequence. We call this flow of information from DNA to RNA to protein
as the central
dogma of life. RNA can easily be copied from DNA by the molecular
complementarity since
they use the same complementary pairs of bases. (The difference
between uracil and thyme
does not hinder the complementarity.) In contrast, protein has no such
obvious
complementarity as in between DNA and RNA. Then, how can the
information in protein
sequence be copied from mRNA? What is the key step in this
inter-lingual communication?
8. Transcription is the process of making RNA from DNA. (Translation
is making protein
from mRNA.) Chromosomes are either closed circles (for eubacteria and
archaebacteria) or
very long linear strings (for eukaryotes). What would happen
physically on these
chromosomes while a region within them is being transcribed?
9. What is the fundamental reason that we can only separate DNA
fragments of about one
thousand bases or so at the very best using the current sequencing
machines?
10. What is the most important discovery done by James D. Watson for
the elucidation of
DNA structure?
