Genetics: Analysis and Principles 5th Edition by Robert Brooker

تمرين 33

Answer the following questions that pertain to the experiment of Figure 14.7
a. Why was -ONPG used Why was no yellow color observed in one of the four tubes Can you propose alternative methods to measure the level of expression of the lac operon
B. The optical density values were twice as high for the mated strain as for the parent strain. Why was this result obtained
FIGURE 14.7 Evidence that the lacI gene encodes a diffusible repressor protein. Starting material: The genotype of the mutant strain was lacI lacZ + lacY + lacA +. The merozygote strain had an F' factor that was lacI + lacZ + lacY + lacA +. The F' factor had been introduced into the mutant strain via conjugation.