This question concernsthree E. coli genes. Genes a and b eachencode polypeptides of 300 amino acids, while gene cencodes a polypeptide of 3,000 amino acids. In trying to isolatemutations for each of these genes, I treated cells with a chemicalto introduce point mutations into the DNA; using this method anynucleotide in the genome has an equal probability of being mutated.I then screened for mutations in each gene. I found that one inevery 10,000 cells carried a mutation in gene a. Thus the mutation frequency for gene a is 1 in 10,000.

a. Given this information,what would you estimate to be the mutation frequency for geneb?

b. What is theprobability that a single bacterial cell would carry mutations inboth gene a and gene b?

c. What would be thelikely mutation frequency for gene c?