16. Which of the following occur in the presence of glucose?

A. lac Z gene expression is increased
B. cAMP increases
C. Binding of CAP-cAMP complex to the promoter area decreases
D. none of the above

17. Sex hormones activate transcription of specific genes by

A. binding to a transcription factor
B. binding to RNA polymerase
C. binding to DNA enhancer region
D. binding to DNA promoter region

18. The lac operon is translated into __________ proteins.

A. 1
B. 2
C. 3
D. 4

19. In the presence of tryptophan in the cell, the repressor is __________

A. bound to tryptophan
B. bound to DNA
C. bound to both DNA and tryptophan
D. bound to neither tryptophan nor DNA

20. Catabolite activating protein exerts __________ control on transcription of the lac operon genes.

A. positive
B. negative
C. may be positive or negative
D. none of these