A potato has to take water from the soil while a plant is growing from it.
In the following experiment you will test what happen to a potato chip in freshwater and to a second one in salt water.
* Cut out two potato chips of exactly the same size.
* Keep the chips in different 10-ml vials, one containing fresh,
   the second containing saltwater.
Observations:
The potato in freshwater increases its volume and is hard, the sample in salt water is smaller and soft.
Explanation: In freshwater more water is taken up by the potato. In salt water water is lost by the potato.
(This is called osmosis).