AP BIOLOGY

Detailed explanation-1: -Active transport requires energy for the movement of molecules whereas passive transport does not require energy for the movement of molecules. In active transport, the molecules move against the concentration gradient whereas in passive transport, the molecules move along the concentration gradient.

Detailed explanation-2: -Passive transport occurs when substances cross the plasma membrane without any input of energy from the cell. No energy is required because the substances are moving from an area where they have a higher concentration to an area where they have a lower concentration.

Detailed explanation-3: -There are two major ways that molecules can be moved across a membrane, and the distinction has to do with whether or not cell energy is used. Passive mechanisms like diffusion use no energy, while active transport requires energy to get done.

Detailed explanation-4: -Passive transport, most commonly by diffusion, occurs along a concentration gradient from high to low concentration. No energy is necessary for this mode of transport.

Detailed explanation-5: -Active transport uses cellular energy, unlike passive transport, which does not use cellular energy. Active transport is a good example of a process for which cells require energy.