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 helps DNA unzip prior to transcription

The blue particles in this image are able to cross the cell membrane through simple diffusion. how will they be transported? outside the cell inside the cell o a. the substances will move directly across the membrane from outside the cell to inside the cell. b. the substances will move through channels in the membrane proteins from outside the cell to inside the cell. o c. the substances will move through channels in the membrane proteins from inside the cell to outside the cell. o d. the substances will move directly across the membrane from inside the cell to outside the cell.