Daily Archives: August 19, 2009

Plant Hormones

germinating beans2

This photograph shows our geotropism experiment, in which we pinned germinating broad bean seeds onto plastic cards with different orientations. No matter which way the beans were orientated, they all showed root growth towards gravity and shoot growth in the opposite direction. They were kept in the dark, so light was not a stimulus. Three more jars were set up with beans that had root-tips removed, shoot-tips removed and both root and shoot-tips removed. We will check these results after the weekend, to determine if the plant root-tip and shoot-tip removal has an effect on growth. More information about plant chemicals (including hormones, alkaloids, flavanoids and tannins) here:

Growth and Plant Hormones from Biology On-line

Plant Hormones

Plant Alkaloids

Tannins and tannins.