How does the lac repressor inhibit transcription?Group of answer choicesIt binds to the RNA polymerase and prevents its association to DNA.It binds to DNA and prevents the RNA polymerase from unwinding and transcribing the DNA.It binds to the RNA molecule, preventing ribosomes from binding.All of the aboveNone of the above

How does the lac repressor inhibit transcription?

Lactose or its analogues act as positive regulators of Lac operon by:Select one:a. Attaching to I gene and preventing its expressionb. Binding to repressor subunits so that the repressor cannot attached to operator locus.c. Increasing the synthesis of catabolic gene activator protein.d. Attaching to promoter region and facilitating the biding of RNA polymerase

The lac operon system, first described by Jacob and Monod, regulates lactose metabolism in . The is composed of a gene encoding a protein that normally keeps this operon in the position. Within the , the repressor binds to the , blocking transcription of structural genes needed for lactose metabolism. When is added to a cell's environment, it binds the repressor freeing the operator segment of the DNA. is now able to bind to the promoter, transcribing all three structural genes needed for lactose catabolism. When lactose again becomes depleted in the cell, the repressor binds to the operator blocking additional synthesis of enzymes from the .

Regulation of bacterial operons by inducers, e.g. lactose, exhibits which of the following properties?(1) Inducer binds to the repressor and __________(2) Inducer effect on RNA polymerase binding to the promoter: ___________(3) Repressor produced by:Select one:A.(1) Activates the repressor, (2) Enhances, (3) A separate geneB.(1) Inhibits the repressor, (2) No effect, (3) A separate geneC.(1) Inhibits the repressor, (2) Inhibits, (3) Genes of the operonD.(1) Activates the repressor, (2) Inhibits, (3) A separate geneE.(1) Activates the repressor, (2) Enhances, (3) Genes of the operon

When RNA polymerase is bound to the lac promoter sequence, transcription of the lac operon is on.