AP BIOLOGY

Detailed explanation-1: -High concentration means the density of the material is greater than what surrounds it. This is in contrast to a lower concentration where the density of material would be less. This is helpful in explaining the natural motion of materials because they naturally move from high concentration to lower.

Detailed explanation-2: -Diffusion: Diffusion is the movement of particles from an area of higher concentration to lower concentration. The overall effect is to equalize concentration throughout the medium.

Detailed explanation-3: -This spread of particles through random motion from an area of high concentration to an area of lower concentration is known as diffusion. This unequal distribution of molecules is called a concentration gradient.

Detailed explanation-4: -During active transport, substances move against the concentration gradient, from an area of low concentration to an area of high concentration. This process is “active” because it requires the use of energy (usually in the form of ATP).