Investigating Osmosis with Onion Cells

In class this week Y10 pupils were investigating the effect of osmosis on red onion cells under the microscope. Pupils added either a drop of distilled water or a drop of sodium chloride solution to onion cells and observed the cells under the microscope.

Joy (10WG) took this picture of her plasmolysed onion cells. Water has moved out of the cells by osmosis and so the cytoplasm in each cell has shrunk to the middle of the cell. This is shown by the purple colour in each cell being only in the middle of the ce 

Krishna (10ER) took this picture of her turgid onion cells. Water has moved into the cells by osmosis and so the cytoplasm is full. This is shown by the purple colour filling each cell.