Explain how T7 promoters regulate transcription and why cloning vectors contain them
What will be an ideal response?
Answer: The bacteriophage T7 polymerase gene is typically cloned on a vector such that it is under regulation of the lac promoter. In this way, analogs of lactose such as IPTG can be exogenously added to the growth medium at any given time to induce expression of the T7 polymerase. The T7 polymerase will recognize only T7 promoters, so only genes downstream to them are turned on in response to IPTG. Many cloning vectors contain T7 promoters upstream of the insert site so that their transcription can be easily manipulated.
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A. theory. B. data set. C. hypothesis. D. conclusion. E. experiment.
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A) It releases histamine into the bloodstream. B) It displays viral proteins on its membrane. C) It synthesizes enzymes that activate helper T cells. D) It secretes steroid hormones. E) It produces interferon.