Select the correct answer from each drop-down menu. the lac operon in e. coli regulates genes that code for enzymes required for breakdown of lactose. the lac operon is operon that is activated in the presence of .

What causes darkening of the skin as melanin production increases

Scientists discover two populations of mice on either side of a major river. the two populations have almost identical genes but the mice from one side cannot breed with mice from the other. this is most likely because

Why is earth's outer core hotter than earth’s oceanic crust? earth’s oceanic crust is denser than earth’s outer core is. earth’s oceanic crust has lava flowing from the mantle. earth’s outer core has a composition of solid iron and nickel. earth’s outer core is deeper within earth than oceanic crust is.