NEET BIOLOGY

Detailed explanation-1: -In molecular genetics, a repressor is a DNA-or RNA-binding protein that inhibits the expression of one or more genes by binding to the operator or associated silencers. A DNA-binding repressor blocks the attachment of RNA polymerase to the promoter, thus preventing transcription of the genes into messenger RNA.

Detailed explanation-2: -The lac repressor protein binds to the operator and blocks RNA polymerase from binding to the promoter and transcribing the operon. The promoter is the binding site for RNA polymerase, the enzyme that performs transcription. The operator is a negative regulatory site bound by the lac repressor protein.

Detailed explanation-3: -A repressor protein binding to the operator gene prevents the transcription of the structural genes for the operon in the absence of inducer.

Detailed explanation-4: -Definition. A repressor, as related to genomics, is a protein that inhibits the expression of one or more genes. The repressor protein works by binding to the promoter region of the gene(s), which prevents the production of messenger RNA (mRNA).

Detailed explanation-5: -lac Repressor blocks transcribing RNA polymerase and terminates transcription.