AP BIOLOGY

Detailed explanation-1: -Raisins swells because of osmosis. Solution outside the raisin has a higher concentration of water molecules. Therefore, water from outside enters the raisin through the process of osmosis and hence the raisin swells up when kept in water.

Detailed explanation-2: -A phenomenon called endosmosis takes place when raisins are placed in water for few hours. When raisins are soaked in water, they swell. All this is due to the process of osmosis. The water molecules pass the cell membrane of the raisins and the raisins thus get swollen.

Detailed explanation-3: -The process that takes place during formation of raisins from grapes is osmosis.

Detailed explanation-4: -When raisins are placed in water they swell up due to endosmosis. The cells of the raisins have a low water concentration. This means that they absorb water and become turgid.