Spotted: How is Water Transported Through Plants?
How is water transported through plants?
- 2 drinking glasses
- Tap water
- Red food coloring
- Celery bunch with leaves
- Adult helper
- Paper towels
- Magnifying lens
- Fill each glass one-fourth full with water.
- In one glass, add enough red food coloring to turn the water bright red.
- Select two stalks from the innermost part of the celery bunch. They should have leaves and a pale green color.
- Ask an adult helper to cut across the bottom of each celery stalk.
- Stand the cut end of one celery stalk in the glass of red water, and the other in the clear water.
- Leave the celery stalks in the glasses overnight.
- Remove the stalks of celery from the glasses, and dry each stalk with a paper towel.
- Use the magnifying lens to study the entire outer surface of each celery stalk.
- Ask your adult helper to cut a 2-inch (5-cm) section from the bottom of each stalk.
- Use the magnifying lens to study the cut surfaces of each section.
- Ask your adult helper to cut a 2-inch (5-cm) section from each stalk at the end nearest the leaves.
- Again, use the magnifying lens to study the cut surfaces of the celery sections.
The leaves and stalk of the celery standing in the clear water are green. The stalk taken from the red water has reddish-colored leaves, and tiny red stripes 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 red in the section cut from the stalk that was in the red water. The surfaces of the cross sections cut at the top and bottom of the same stalk are similar.
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 red food coloring stains the thick walls of the xylem tubes, so they appear as red 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.
Try It With A Microscope
- Ask your adult helper to cut a very thin slice from each stalk of celery.
- Place the slices on separate microscope slides.
- Observe and make a drawing of each slide as seen through the microscope.
Small, colorless cells crowd together around the outer edge of the celery slices, surrounding larger cells, which are side by side in the center. Large, dark-looking masses appear near one edge of each slice and are red on one of the slices.
Do flower stems contain xylem tubes? Repeat the original experiment using a white carnation. Science Fair Hint: Make colored diagrams of the results of the experiment and use them as part of a project display.
Are xylem tubes connected to each other? With the help of an adult, cut the stem of a white carnation lengthwise about halfway up the stem. Carefully separate the two halves, placing one in a glass of blue-colored water and the other in a glass of red-colored water. Observe the color of the flower after 48 hours. Study slices of the flower's stem under a microscope or magnifying lens. Photographs of the flower petals before and after the experiment can be used as part of a project display.
Warning is hereby given that not all Project Ideas are appropriate for all individuals or in all circumstances. Implementation of any Science Project Idea should be undertaken only in appropriate settings and with appropriate parental or other supervision. Reading and following the safety precautions of all materials used in a project is the sole responsibility of each individual. For further information, consult your state’s handbook of Science Safety.