Grade:
Time:
Topic:
Concept:
SOL: Science:
Rationale:
Goals:
Objective:
Materials:
- a green plant with six leaves
- petroleum jelly
- science journal
Choose six leaves. Coat the top of two of the leaves with petroleum jelly, and then coat the undersides of two leaves with petroleum jelly. Leave two leaves untouched. Check the leaves each day for a full week.
Procedure:
What do you notice about the two sets of leaves? Ask students to write a hypothesis about the leaves. What do they predict will happen to the leaves with petroleum jelly on the top? What about the ones whose undersides are sealed?
Why?
The undersides of leaves have openings called stomata, which allow gases from the atmosphere to move into and out of the leave. The petroleum jelly plugged the openings and the leaf was not able to receive necessary carbon dioxide gas or eliminate excess oxygen gas.