For example, the World Health Organization recommends keeping added sugar intake to 10% of total calories. For the average 2000 calorie-diet that's a maximum of 50 grams. The American Heart Association recommends 6 teaspoons of sugar for women and 9 for men (1 teaspoon of sugar has about 4g of sugar).
In developmental biology, cellular differentiation is the process by which a less specialized cell becomes a more specialized cell type. Different tissues have different kinds of cells.
Cellular diffusion is the process that causes molecules to move in and out of a cell. Molecules move from an area of high concentration to an area of low concentration. When there is a higher concentration of molecules outside of a cell, then more molecules enter the cell than leave. When there is a higher concentration of molecules inside of a cell, then more molecules leave the cell than enter.