To demonstrate that the leaves and stems of plants can act like a straw
1. Form clay into a ball and then slightly flatten it until it is slightly larger than the opening of the test tube.
2. Poke two holes near the center of the clay with the tip of a pencil. make sure that the holes are made all the way through the clay. One hole needs to be large enough to put the ivy through and the other large enough to fit the straw through.
3. Pull ivy stem until leaf is touching the clay and insert the straw in approximately half way.
4. Seal the clay around the stem and straw tightly so no air can get through.
5. Make sure the bottom of stem and straw are not plugged up by clay.
6. Fill the test tube approximately three-quarters full of water.
7. Insert the stem and straw into the test tube. The stem should extend into the water; the straw should not be in the water but instead in the air space above the water.
8. Seal the clay tightly around the top of the test tube.
9. Holding the test tube toward the bottom, make sure you have a clear view of the bottom of the stem.
10. Holding the mirror so that you can see the bottom of the stem, start sucking very hard on the straw. Observe the bottom of the stem and record observations.
Bubbles start forming at the bottom of the stem
There are holes in the leaf called stomata, and tiny tubes called xylem run down the stem. The leaf and stem act as a straw. As you sucked air out of the straw, more was drawn in through the leaf straw. It is through these tubes and holes that water moves in a plant.
Kelley Bassett, 2000.