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