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71. The initiator sequence and promoter sequences must exhibit a large degree of overlap.
72. If the lac operon was designed this way, LacI would only have a high affinity for DNA in the
presence of lactose.
73. This operon design could be used to inhibit gene expression in response to the presence of an
environmental chemical (Remember the arg operon question 2 from the Chapter 6 Problem Set?)
74. For this mechanism of regulating gene expression to be effective, the regulatory gene would
have to possess a strong promoter. Answers to “more Practice final exam questions”:
B LacI can’t bind operator, or lac operator can’t bind LacI. See 80.
Since there is an overlap in sequence of the promoter and operator.
So there is continuous supply of LacI. However, only small amounts are
required; so, promoter of lacI gene is not strong…
Effector binds to LacI.
Mutation in structural genes refer to phenotype that is different from wild
type. The gene is still present and will be expressed makin...
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