Tuesday, July 6, 2010

LEAF STRAW

PURPOSE : To demonstrate that the leave and stem of plants can act like a straw.

MATERIALS : Glass soda bottle
                           Ivy leaf and stem
                          Clay
                          Straw
                          Pencil
                          Mirror

PROCEDURE :

  • Fill the bottle to within an inch of its top.
  • Wrap the clay around the stem near the leaf.
  • Place the stem into bottle. The end of the stem must be below the surface of the water.
  • Cover the mouth of the bottle with the clay.
  • Push the pencil through the clay to make an opening for the straw.
  • Insert the straw so that its opening is in the air space at the top of the bottle.
  • Squeeze the clay around the straw.
  • Stand in front of the mirror and look at the mirror image of the bottle while you suck the air out of the bottle through the straw.This should be difficult if there are no leaks in the clay so use a lots of suction.
RESULTS : Bubbles start forming at the bottom of the stem.

WHY ? There are holes in the leaf called stomata, and tiny tubes called xylem run down the stem. The leaf and stem acted like a straw. As you sucked air out of the straw through the leaf straw. It is through these tubes and holes that water moves in a plant.

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