Explain the processes of active and passive transport- include their similarities and differences?

Both passive and active transport move substances into and out of the cell across the cell membrane. However, passive transport does not require the use of energy because molecules move from an area of high concentration to an area of low concentration. Active transport does require the use of energy because molecules move from an area of low concentration to an area of high concentration.

answer; i believe the correct answer is ( proteins );

the element that provides strength to the exoskeletons of clams and oysters is phosphorus. this is so because calcium carbonate is the main component in the shells.

explanation: