Attenuation of trp operon transcription is controlled by the formation of stem-loop structures in mRNA. The attenuation function can be disrupted by mutations that alter the sequence of repeat DNA regions 1 to 4 and prevent the formation of mRNA stem loops. Describe the likely effects on attenuation of each of the following mutations under the conditions specified.

Mutated Region        Tryptophan Level
a. Region 1                        Low
b. Region 1                        High
c. Region 2                        Low
d. Region 2                        High
e. Region 3                        Low
f. Region 3                         High
g. Region 4                        Low
h. Region 4                        High