Which describes a promoter? the first part of an operon that regulates where, when, and to what level a gene is expressed the part of an operon that, if attached by a repressor protein, suppresses the expression of a gene a cluster of genes that are expressed or repressed as a group an enzyme that dna unzip prior to transcription

A promoter is described as the first part of an operon that regulates where, when, and to what level a gene is expressed.A promoter is a sequence of DNA that is found upstream of the sequence of the gene that is to be expressed.The promoter is responsible for regulating the expression of genes as it is the site where the RNA polymerase comes and bind to initiate transcription. Thus the location of gene expression in the DNA and its timings as well a the level of gene expression is regulated by the promoter sequence.

The correct answer is a. we know this because n (hap) + n (hap) = 2n (dip).