LIFE SCIENCE

Detailed explanation-1: -Diffusion is the net movement of molecules from an area where they are at a higher concentration to areas where they are at a lower concentration. This is due to the random movement of the molecules. The difference in the concentration of a substance between two areas is called the concentration gradient .

Detailed explanation-2: -In cells, to maintain a balance (equilibrium) of substances inside, substances will move from high concentration to low concentration through plasma membrane. This means if contents inside the cell is more they will move to outside and vice-versa.

Detailed explanation-3: -The difference in the concentrations of the molecules in the two areas is called the concentration gradient.