This practical involves allowing a growing plant to enter a simple maze made from a cardboard box. Thanks to the mechanics of phototropism, the shoot should find its way through the maze to the open end over a period of time.
Equipment typically required (per set):
- Small sprouting plant (beans work well)
- Sticky tape
A hole is cut in each end of a shoebox. One of these will be the entrance to the maze and the other will be the exit hole. Inside the box, stick pieces of cardboard in place to create a simple maze. Make sure that if you look into one end hole, you cannot see the opposite hole so that the sprouting bean has to move around the maze. The diagram above shows the kind of maze that is suitable for this.
Make a few dead ends and ensure that when closed, the box does not leak too much light.
The plant should be placed near the bottom opening of the maze and a single shoot should be placed inside the opening. The box may need to be mounted securely but the lid should be free to open so you can check the plant’s progress. Try to leave a small gap between the plant and the maze opening so that excessive light can not get into the box.
Over the course of a few weeks, the shoot should have made its way out of the top of the maze and towards the light. This process is known as phototropism. Most plants will move towards a light source and will bend to achieve this.
Beans are perfect for this practical as they are fast growers and produce long spindly shoots.