Photomacrograph; color transparency film; x2.6 approximate magnification

Bio-Graphics, Blue Bell, Pennsylvania, United States

This image demonstrates the results of an experiment proving the existence of blue light photoreceptors in thale cress, Arabidopsis thaliana, seedlings. There is a normal inhibition response to growth when the photoreceptor detects blue light conditions. The control seedling (right) exhibits stunted growth, indicating the presence of the receptor. In the experimental genome (left), it has been removed and the plant does not recognize the specific wavelength of blue, thereby growing normally. (The experimental seedling is approximately 1 cm tall.)