Adaptation, Physiological, Eukaryota - physiology, Chloroplasts - ultrastructure, Snow, Cyanobacteria - ultrastructure, Mitochondria - ultrastructure, Marine Biology, Cyanobacteria - radiation effects, Ultraviolet Rays, Chloroplasts - radiation effects, Mitochondria - radiation effects, Fresh Water, Eukaryota - ultrastructure, Eukaryota - radiation effects