Science

How is water transported through plants?

23 Jul , 2014   Video

This small experiment will help to see how water is transported in plants.

Materials

  • 2 drinking glasses
  • Tap water
  • Blue food coloring
  • Celery bunch with leaves
  • Paper towels
  • Magnifying lens

Procedure

  1. Fill each glass one-fourth full with water.
  2. In one glass, add enough blue food coloring to turn the water bright blue.
  3. Select two stalks from the innermost part of the celery bunch. They should have leaves and a pale green color.
  4. Cut across the bottom of each celery stalk.
  5. Stand the cut end of one celery stalk in the glass of blue water, and the other in the clear water.
  6. Leave the celery stalks in the glasses overnight.
  7. Remove the stalks of celery from the glasses, and dry each stalk with a paper towel.
  8. Use the magnifying lens to study the entire outer surface of each celery stalk.
  9. Ask your adult helper to cut a 2-inch (5-cm) section from the bottom of each stalk.
  10. Use the magnifying lens to study the cut surfaces of each section.
  11. Cut a 2-inch (5-cm) section from each stalk at the end nearest the leaves.
  12. Again, use the magnifying lens to study the cut surfaces of the celery sections.

Results

The leaves and stalk of the celery standing in the clear water are green. The stalk taken from the blue water has  bluish-colored leaves, and tiny  blue tripes can be seen running down its entire length beneath the surface. Sections cut from both stalks have a single row of tiny dots near one outer edge. These dots are blue in the section cut from the stalk that was in the  blue water. The surfaces of the cross sections cut at the top and bottom of the same stalk are similar.

Why?

The cross sections of the celery stalk revealed that the colored water rose from the bottom of the stalk through tiny tube like structures to the top of the stalk. These water-carrying vessels in plants are called xylem tubes. The  blue food coloring stains the thick walls of the xylem tubes, so they appear as  blue circles on the cross sections. In nature, xylem tubes transport a liquid mixture of water, sugars, and minerals up to the leaves of the plant. This watery mixture is called sap.

 


Leave a Reply

Your email address will not be published. Required fields are marked *