When a repressor binds to the operator site on the DNA it normally

A. inhibits the initiation of transcription.
B. has no effect on transcription.
C. terminates transcription that has already been initiated.
D. reduces the rate of transcription.


Answer: A

Biology & Microbiology

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In humans, ability to roll the tongue (R) is dominant to being unable to roll (r). Having freckles (F) is dominant to having no freckles (f)

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A molecular biologist is interested in purify a recombinant protein by His-tagging, but the protein and vector both lack histidine residues. In this case, the molecular biologist could use which of the following technique(s) to achieve purification?

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