Here’s what you’ll need:
1. 6 Stalks of celery, at least 6 inches long
2. 6 Drinking glasses
3. A 1-cup measuring cup
5. Red or blue food coloring
6. A knife (have an adult help you with this!!)
7. A cutting board
8. Paper towels
9. A ruler
Here’s what to do:
1. Cut the pieces of celery so they are all the same length. Cut only the bottom (root) end, leaving any leaves at the top. Try to leave the stalks as long as possible!
2. Measure one cup of water into each of your six glasses.
3. Put 10 drops of food coloring into each glass.
4. Add a stalk of celery to each glass, the cut end submerged in the water.
5. After two hours, remove one stalk of celery, and dry it off with a paper towel. Take a look at the bottom of the stalk that was in the water. Do you see any color change? Cut the stalk in half from the bottom to the top (lengthwise), and using your ruler measure how far from the bottom end the dye has traveled. The small tubes that have changed color are the celery’s xylem!
6. Measure the water left in the glass. Write down how much is left.
7. Write down all your observations, like what color the celery is changing, and how far up the celery the dye has traveled!
8. Do this again after 4 hours, 12 hours, 24 hours, and 48 hours. Be sure to write down any changes you see in the celery, and how far the dye has traveled each time.
What happened to the dye? Why do you think this happened? Now that your experiment is done, how much water is left in the final glass? Is this what you expected?
What else can you do with your celery? What would happen if you changed the conditions, like putting the glasses with the celery in the sun, or in a dark cupboard? What about if you put the glass with the celery in a re-sealable plastic bag, and sealed it up during the experiment? Use your imagination, and try new things, but always be sure to write everything down, like what you are doing, and what you see during your experiment!
References for further reading:
1. McElrone, A J; Choat, B; Gambetta, G A; Brodersen, C R . (2013) Water Uptake and Transport in Vascular Plants. Nature Education Knowledge 4(5):6
2. Plants: Essential Processes, Water transport. SparkNotes. Retrieved 4-10-14. http://www.sparknotes.com/biology/plants/essentialprocesses/section1.rhtml
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