Some raisins were added to a rice pudding. After a while, it was observed that the raisins had swollen up. What is the scientific phenomenon behind the swelling…

Hypotonic, Endosmosis

Reason — The pudding around the raisins has a lower solute concentration than the cell sap of the dried raisins, so it is hypotonic to them. Water therefore moves into the raisins through their semi-permeable membranes by endosmosis and they swell up.