Which parts of the DNA region shown in the diagram encode proteins? (I = lac repressor gene; Z, Y, A = lac operon structural genes; P = lac promoter; O = lac operator)
A)P
B)I, P, O
C)P, O, Z, Y, A
D)I, Z, Y, A
E)I, P, O, Z, Y, A

Question

Which parts of the DNA region shown in the diagram encode proteins? (I = lac repressor gene; Z, Y, A = lac operon structural genes; P = lac promoter; O = lac operator) 
A)P 
B)I, P, O 
C)P, O, Z, Y, A 
D)I, Z, Y, A 
E)I, P, O, Z, Y, A

Quizplus · Accepted Answer

Only the structural genes Z, Y, and A encode proteins. The lac repressor gene (I) encodes a regulatory protein, while the lac promoter (P) and operator (O) are non-coding regions involved in transcriptional regulation.

Which Parts of the DNA Region Shown in the Diagram