fotoperiodizmus
Fotoperiodizmus is the physiological response of organisms to the relative lengths of day and night. This phenomenon plays a crucial role in regulating various life cycle events, particularly in plants and animals. For plants, photoperiodism is essential for controlling processes like flowering, germination, leaf fall, and dormancy. Plants can be classified based on their flowering response to day length: short-day plants flower when days are shorter than a critical length, long-day plants flower when days are longer than a critical length, and day-neutral plants are not affected by day length. The photoreceptor responsible for detecting these light cues in plants is primarily a pigment called phytochrome. In animals, photoperiodism influences breeding seasons, migration patterns, hibernation, and molting. The detection of light changes in animals often involves the eyes and specialized photoreceptor cells in the brain, such as those in the pineal gland, which can regulate hormone production in response to light signals. This temporal environmental cue allows organisms to synchronize their internal biological clocks with seasonal changes, ensuring optimal timing for reproduction, survival, and other vital activities.