A cell has evolved in an environment that lacks a particular food source. However, when given this food in the laboratory, it is able to digest and use it for energy. Which of the following is likely true about the operon used to produce the enzymes needed for this metabolic process? O A. The repressor is produced in the active state which causesst to bind to the operator. B. The repressor is produced in the inactive state which causes it to bind to the operator. O C. The repressor is produced in the active state which causes it to bind to the promoter. O D. The repressor is produced in the inactive state which causes it to bind to the promoter.

Which of the following statements is true regarding transcriptional attenuation of the trp operon? a. The leader peptide encodes a protein that binds to the operator site b. Translation of the leader peptide stalls when tryptophan levels are high c. Stalling of the ribosome in region 1 of the leader peptide inhibits formation of the transcriptional terminator sequence d. This kind of mechanism can only occur in prokaryotes e. Both c. and d. are true

You are growing E. coli in a laboratory in order to study their operons. The growth media you are using contains lactose, no glucose and no tryptophan.  Using your knowledge of operons and their regulation   a.Which operons would be functional under these conditions? b.What repressors would be made? (NOTE: name the repressors using their gene names) c.Which repressor(s) would be made in the inactive form? d.Which repressor(s) would be made in the active form? e.Which repressor(s) under these conditions can bind the operator sequence? f.Which repressor(s)under these conditions cannot bind the operator sequence?

The lac operon is an operon that is:   Group of answer choices A turned off whenever tryptophan is added to the growth medium. B permanently turned on. C turned on only when glucose is present in the growth medium. D turned off only when glucose is present in the growth medium. E turned on when lactose is present in the growth medium.

In the tryptophan operon, if the leader peptide is translated normally   A region 2 will pair with region 3   B a rho independent terminator will form.   C both a and b   D none of the above

Which of the following molecules will experience a large change in cytoplasmic concentration whenthe above tryptophan operon is turned on (in E. coli cells)?A. tryptophan molecules will decrease in concentrationB. lactose molecules will decrease in concentrationC. tryptophan molecules will increase in concentrationD. lactose molecules will increase in concentrationE. none of the above

Control of the trp operon relies on which of the following: a. High levels of tryptophan causing a pause (but not termination) in transcription b. Low levels of tryptophan causing a pause (but not termination) in transcription c. Allolactose binding to the inhibitor to prevent it from binding to the promoter d. Tryptophan binding to the inhibitor to prevent it from binding to the promoter