Answer:
Diffusion through a semi-permeable membrane
Explanation:
A membrane that would only allow water, ions and certain molecules to pass through it by diffusion while restricting other large molecules molecules from passing through is called semi-permeable membrane
The iodine molecules were dissolved in the water in the beaker to form iodine solution.When the starch in the tubing was immersed into the red iodine solution, the molecules of iodine diffuse across the tubing walls which acts as the cells membrane -selectively permeable membrane to react with the starch solution. The reaction turns the starch blue black
The characteristic of the cell membrane is due to the lipid bi-layer which allow certain substance pass through while restricting others because of the inner hydrophobic (water hating) and outer hydrophilic phospholipid layer. (water loving layer)These forms the double bi layer to selectively control the movement of substances across it.
