Biological rhythms are natural cycles that occur in living organisms, regulating various physiological processes. These rhythms can be daily, such as the circadian rhythm, which influences sleep-wake cycles, or longer cycles like ultradian rhythms, which occur multiple times within a day. These rhythms help organisms adapt to their environment and maintain homeostasis. For example, the sleep-wake cycle is influenced by light exposure, while seasonal changes can affect reproductive cycles in some animals. Understanding biological rhythms is essential for studying health, behavior, and the effects of disruptions like jet lag or shift work.