Final answer:
A cycle of bodily rhythm that occurs over a 24-hour period is known as a circadian rhythm, which is a type of biological rhythm that regulates various physiological processes and is controlled by the biological clock in the brain.
Step-by-step explanation:
A cycle of bodily rhythm that occurs over a 24-hour period is known as a circadian rhythm. This biological rhythm is an internal cycle that regulates numerous physiological processes, including body temperature, hormone levels, sleep-wake patterns, blood pressure, and many other aspects of homeostasis. The biological clock, a structure located at the base of the brain, plays a key role in controlling these rhythms, which are influenced by environmental cues such as light and darkness. The term circadian comes from Latin, meaning 'about a day,' reflecting the approximate duration of this cycle.
Notable examples of circadian rhythms include the sleep-wake cycle, which is closely aligned with our environmental light-dark cycle. Changes in body temperature and blood pressure also follow a circadian pattern, peaking and dipping at certain times during the 24-hour day. Even cellular processes such as the cell cycle are influenced by these rhythms, providing evolutionary advantages in response to environmental factors.
Thus, to answer the question, a cycle of bodily rhythm that occurs over a 24-hour period is known as circadian rhythm (Option 1).