1. Why do plants always grow the correct way? The stems and leaves always grow up, and the roots always grow downward, but, how do they know which way is which? What keeps them from getting confused and growing upside down? Look up the word "auxin" and describe its function.
2. What does the word geotropism mean?
3. In a Petri dish bottom, place some wet paper towels. On the paper towels, place four bean seeds that have been soaking for a couple hours in water. Place the beans so that the micropyle of each is facing the middle of the dish. Make sure there is enough paper towel in the dish so that the beans will not shift once the lid is taped in place. Tape the lid in place and stand the dish on its side. In the circle below, show how you arranged the bean seeds in the Petri dish. Observe the seeds over the next few class periods and draw what you see.
4. On the back of this sheet, explain how gravity and auxin help plants always grow in the right direction.