In this experiment we investigated how a high or low mutation rate of E. Coli will affect its growth in a lactose medium and whether different concentrations of each of the strains would produce different results. We hypothesized that a higher mutation rate would result in more lactose digestion among the E. Coli cultures and that a higher concentration of either strain would produce more lactose digesting cells, and normal unmutated cells as well. As previously predicted, the results below show that the greater the plated concentration of E. Coli, the more mutated lactose digesting cells there were after a week of growth. However, one thing of note is that the low mutator plates especially the 10^3 concentration, produced more similar growth …show more content…
This trend sheds a little light on how exactly mutations are affecting the E. Coli bacterium. Since mutations can be both beneficial and deleterious, it is difficult to predict how these mutations will affect how the organism interacts with its environment. For example, a frameshift mutation could cause the lac operon to not code for the enzymes necessary for lactose digestion hence decreasing its fitness in lactose filled medium. On the other hand, a mutation such as an error in the coding of the lac operon repressor could increase the rate of lactose metabolism, thus improving its fitness. However, by interpreting the data, one conclude that despite the deleterious mutations produced by the high mutating strand, it was still beneficial for E. Coli to be a high mutator. There are two explanations for this conclusions: one is that it is more likely for an E. Coli bacteria to receive a mutation that increases its lactose metabolism and thus its fitness in a lactose medium, than it is for them to acquire a deleterious mutation that would decrease their fitness. This could be due to the fact that there are more possible sites for beneficial lactose digestion mutations and limited sites for the deleterious mutations. Secondly, it is also possible that the high mutating bacteria received an equal amount of deleterious and beneficial mutations, but that those with a deleterious