What is Stomata?

Question:   What side of a plant leaf takes in gases?

Hypothesis:  Ten (10) students say the top of the leaf takes in gases because when rain and watering cans water plants it comes from above and hits the top of the plant leaves first. Ten (10) say  the bottom of the leaf takes in gases because after observing the leaves from each plant the bottom of the leaves were more veiny  and the skin of the bottom leaves seemed thinner.  The top of the plant  leaf had a thicker, waxy covering and it looked like water would be hard to get through it.

Materials:  Two varieties of plants Vaseline  A  Camera

Procedure:  Coat the top of four leaves from each plant with a heavy layer of Vaseline. Coat the underside of four leaves from each plant with a heavy layer of  Vaseline.  Observe the leaves daily for one week.  Is there any difference in the two sets of leaves?

Results:       Three of the four  leaves that had Vaseline on the underside, died. Only one leaf with vaseline on the top died. Therefore, we believe that plant leaves take  in gases from the bottom, not the top, of each leaf.

Why:           Openings on the underside of plant leaves called stomata allow gases to  move into and out of the leaves.  The vaseline plugged the openings and the leaf was not able to receive the necessary carbon dioxide gas or eliminate excess oxygen gas.