Problem 5: It has been estimated that the spontaneous mutation rate per cell division for each gene in humans is about 10 However, there are about 1013 cells in the adult human body. a) Using the crude model that our cells are derived from synchronized doubling cycles (1 cell goes to 2 cells goes to 4 cells, etc.), how many synchronized doubling cycles are needed to go from one fertilized egg cell to 1013 cells? b) The chance that a gene in a cell has a mutation is closely related to the probability that one cell in its lineage had this mutation. Estimate the gene mutation probability for a cell in adulthood based on your answer in (a) and a the mutation frequency 10-6 c Using your simple estimate in (b), and assuming that mutation of one copy of p53 does not accelerate mutation of the other copy, estimate the probability that both copies of p53 are simultaneously mutated in a cell As an aside, our simple estimates suggest that the low mutation rate set by cell cycle checkpoints, etc, is still relatively high when compared to the number of cells in our body. You can conclude correctly that other kinds of error correction exist to address the problem of mutation.