In a bacterial operon:a) all of the operon genes are transcribed into a single RNA molecule b) the inducer must be a sugar c) the inducer must be a protein d) regulation occurs at the level of translation e) all of the genes are constitutive genes.

The table below shows the elements that mainly comprise each of the four layers of earth: elements in layers layer main elements crust oxygen, silicon mantle iron, magnesium outer core iron, nickel inner core iron which of these elements make up the layer that is 0.2 to 1.1 percent of earth's total diameter?