Osmosis is defined as the passive transport in which net movement of water across the membrane from high water area potential to low water area potential. The membrane is known as selectively permeable membrane moved by a concentration of solute both sides of the membrane.
Selectively permeable membrane is a membrane which is selective in nature that allows unrestricted passage of water molecules, but not solute molecules.
If they didn't differentiate then the stem cells would stay the same type and if it somehow kept multiplying then they would just be a massive blob with no actual form or way of functioning.
