Geotropism

We made this clinostat at work to show geotropism by attaching a Petri dish to the hour hand of a clock mechanism, adding cotton wool and cress seeds. Geotropism describes the plants response to the force of gravity, the upward growth of the shoots is negative geotropism and the downward growth of the roots positive geotropism. The clinostat rotates once an hour so the seedlings don't know what is up or down resulting in wonderfully higgledy piggelty growth as you can see.
I do love my job, though it was Debs who set this wonderful experiment up!