Osmosis is the flow of water down its concentration gradient, across a semi-permeable membrane. ... An everyday example is the plastic wrap in your kitchen: it allows air and water vapor to travel across it, but not water or food. The membranes of cells are semi-permeable, too.
Two chromosomes that are similar but not identical are called homologous chromosomes. When the chromosomes are duplicated, two identical chromosomes are called sister chromatids.
