The promoters of positively controlled operons require activator proteins because The promoters of positively controlled operons require activator proteins because they are needed to bind to the allosteric site of RNA polymerase. RNA polymerase easily recognizes the consensus sequence. the promoters bind RNA polymerase weakly and utilize activator proteins to help RNA polymerase recognize the promoter. they are required to inactivate the repressor proteins.

the promoters bind RNA polymerase weakly and utilize activator proteins to help RNA polymerase recognize the promoter.

Explanation:

The promoters of positively controlled operons require activator proteins because the promoters bind RNA polymerase weakly and utilize activator proteins to help RNA polymerase recognize the promoter.

most community's take hundreds of years to become stable

genetic variation can be caused by mutation (which can create entirely new alleles in a population), random mating, random fertilization, and recombination between homologous chromosomes during meiosis (which reshuffles alleles within an organism's offspring).