Suspend the carrot in water, resting the toothpicks on the rim of the cup. Leave for a day or two and watch what happens. When a carrot grows in the ground, its cells transfer the water in the ground up to the stalks and leaves above ground by a process called osmosis. You can see osmosis at work in this activity. Osmotic pressure has pushed water up into the straw.
Osmotic pressure is a kind of pump for plants, helping water to move across cell walls.
Colour the water with ink or food colouring. After the water has risen in the straw, cut the carrot in half. Try putting limp carrot sticks in fresh water.