Problem Set 6 – Problems on Gene Expression/Repair and Protein Synthesis/Degradation (3
16. The DNA in a human non-gametic cell contains 6 billion base pairs. It is estimated that
about 10,000 DNA changes occur in each cell in one day. These are quickly repaired so that
only a few (1 to 5) mutations accumulate in one cell in a year.
a. What percentage of the base pairs are altered each day?
b. What percentage of the DNA changes that occur in one cell in one year escape
the proofreading and repair process – calculate this in both cases: if 1 mutation
accumulates in one cell per year, and if 5 mutations accumulate in one cell per