In the function of the lac operon in E. Coli, the lac genes are transcribed in the presence of lactose because a) RNA polymerase binds to the operator b) the repressor cannot bind to the promoter c) an isomer of lactose binds to the repressor d) CAP does not bind to the operator

Red blood cells are responsible for transporting oxygen in the blood. people with sickle cell anemia were born with a defective gene that results in sickle-shaped red blood cells. individuals with the disease often suffer pain in their extremities due to the build-up of these cells causing blockages in the blood vessels. the shape of the blood cells also reduces the amount of oxygen transported in the blood.