Consider the following experiment. A plant is set in one corner of a box. A top is put on the box so that the hole in the top is opposite to the plant.
Over the next week, the plant in the box should:
grow downward
grow away from the hole
bend and grow towards the hole
die for lack of air
It will bend and grow towards the hole because the sunlight will shine through the hole and the plant will sense it so it will grow towards the light. I hope I could help you :)
