Section 3. Answer the following problems assuming that gene Z is regulated by the following regulatory network. Presume that B, C and D are proteins each with their own gene and that the interactions are showing how the proteins regulate the specific promoters. Assume that stimulus A is a metabolite and the arrow shows how its binding to protein B influences that protein's DNA binding activity. Assume that the organism is haploid.



22. Which of these statements is completely true about the WT situation above?
A. Gene Z is expressed in the presence of Stimulus A and blocked in the absence of A
B. Gene Z is blocked in the presence of Stimulus A and expressed in the absence of A.....
C. Gene Z is blocked in the presence of Stimulus A and blocked in the absence of A
D. Gene Z is expressed in the presence of Stimulus A and expressed absence of A
E. Doh

23. Which of these statements is completely true if C is a dominant mutant that cannot be blocked by B?
A. Gene Z is expressed in the presence of Stimulus A and blocked in the absence of A
B. Gene Z is blocked in the presence of Stimulus A and expressed in the absence of A
C. Gene Z is blocked in the presence of Stimulus A and blocked in the absence of A
D. Gene Z is expressed in the presence of Stimulus A and expressed absence of A...........
E. Doh

24. Which of these statements is completely true if C is a recessive mutant that cannot activate D?
A. Gene Z is expressed in the presence of Stimulus A and blocked in the absence of A
B. Gene Z is blocked in the presence of Stimulus A and expressed in the absence of A
C. Gene Z is blocked in the presence of Stimulus A and blocked in the absence of A.........
D. Gene Z is expressed in the presence of Stimulus A and expressed absence of A
E. Doh

25. Which of these statements is completely true if B is similar to the iS mutant?
A. Gene Z is expressed in the presence of Stimulus A and blocked in the absence of A
B. Gene Z is blocked in the presence of Stimulus A and expressed in the absence of A
C. Gene Z is blocked in the presence of Stimulus A and blocked in the absence of A
D. Gene Z is expressed in the presence of Stimulus A and expressed absence of A.........
E. Doh

26. What is trans to Gene Z? Answer with all 100% true possibilities.
A. A
B. B
C. C
D. D.....
E. Z

From test 11 Bis 101 can anyone help me figure out how to solve this problem.