Striped Celery Snack: How Water Moves Up Stems
One of the important jobs of plant stems is to carry water from the roots to the leaves. You can see how this happens with a stalk of celery and some food coloring.
Materials & Equipment
Procedure 1
Which parts of the stem have the most food coloring? The long strands that carry water are called the xylem. Xylem is made of hollow cells that form a pipeline from roots to leaves. You can see where the xylem is in celery by cutting across the stalk. Procedure 2 Repeat this experiment using 2 stalks of celery. One stalk should be quite leafy and the other should have no leaves. Observations In which stalk does the water reach the top of the stem first? Procedure 3 1. For this experiment use two leafy stalks of celery. Put one glass with its celery stalk in the sunlight and keep the other in the shade, covering the celery with a small plastic bag. Observations In which stalk does the water rise more quickly? How do your findings support the theory that the speed with which water rises in plants is a result of how fast water evaporates from the leaves? You can eat the celery when you have finished your experiments. It's good with some peanut butter or cream cheese spread down the middle. Try putting other vegetables in colored water. See if you can find the xylem in white radishes, scallions, and carrots. Choose a dark-colored dye that will show up against the color of the vegetables. |