Effects of ultraviolet radiation
on biological systems
"All animals are equal, but some animals are more equal than others" (George Orwell "Animal Farm", 1945). The picture above shows the poodle Tesla considering to become a vegetarian.
Photobiology deals with effects of light and ultraviolet radiation on organisms, and with the emission of light by organisms. Among the more important topics are photosynthesis, photoperiodism, vision, orientation in relation to light direction, photoinactivation and photoreactivation of DNA, regulation of gene activity by light and ultraviolet radiation, phototoxicity, photomedicine, and bioluminescence.