AP BIOLOGY

Detailed explanation-1: -Passive transport does not require the cell to expend any energy and involves a substance diffusing down its concentration gradient across a membrane.

Detailed explanation-2: -In passive transport, substances simply move from an area of higher concentration to an area of lower concentration, which does not require the input of energy. Concentration gradient, size of the particles that are diffusing, and temperature of the system affect the rate of diffusion.

Detailed explanation-3: -In active transport, the molecules move against the concentration gradient whereas in passive transport, the molecules move along the concentration gradient.

Detailed explanation-4: -Solutes move with the concentration gradient, therefore no energy is used. Movement of materials from high to low concentration through a protein channel.

Detailed explanation-5: -Passive modes of transportation include: Solutes move from a higher concentration region to a lower concentration region by simple diffusion. In facilitated diffusion, solutes move through a membrane from higher to lower concentrations with the aid of transmembrane proteins.