In mice, a diet rich in methyl groups (e.g., rich in folic a…

In mice, a diet rich in methyl groups (e.g., rich in folic acid) leads to the methylation of the agouti gene that controls coat color and obesity. A mother mouse fed this diet generally produces more offspring with brown fur who are thin, and fewer offspring with yellow fur who are obese. What does this example illustrate?

The lac operon in E. coli bacteria contains genes necessary…

The lac operon in E. coli bacteria contains genes necessary for the metabolism of lactose. When lactose is absent, a repressor protein binds to the operator region of the DNA, preventing RNA polymerase from transcribing the genes. What is the role of this repressor protein?