This experiment shows how water is transported through plant stems.
Things Required:
Measuring cup (250 ml)
2 glasses
1 white carnation with a long stem (purchase at a floral shop)
Red and blue food colouring
Directions:
Ask an adult to cut the stem in half lengthwise from the bottom to about half way up towards the flower. Pour 1/2 cup of water into each glass.
Add enough food colouring to make the water in each glass a deep colour; one will be blue and the other red. Place one end of the flower stem in the blue water and the other end in the red water.
Leave the flower standing in the water for 48 hours.
This Is What Happens:
After 48 hours, the flower will have changed colour. One side will be red and the other blue.
Science Behind It:
Tiny tubes, called xylem, run up the stalk to the flower petals. The coloured water moves through the xylem allowing the colour to be distributed throughout the cells in the petals causing their colour to change. Minerals in the soil are carried to plant cells in this way providing nutrients to flowers and leaves. The minerals dissolve in water as did the red and blue colouring and the solution is carried up to the leaves and the flowers where the dissolved material is left as was the red and blue dye.
