Correct option is C
The term "zeitgeber" (German for "time giver") refers to external cues that help synchronize biological rhythms with the environment. These cues play a crucial role in regulating circadian rhythms, which are physiological cycles that follow a 24-hour pattern.
Main Zeitgebers in Humans and Animals:
- Light: The most dominant zeitgeber, regulating the sleep-wake cycle.
- Temperature: Changes in environmental temperature influence metabolic and behavioral rhythms.
- Meal Timing: Eating patterns affect metabolic and digestive rhythms.
- Social Cues: Work schedules, social interactions, and routines act as secondary zeitgebers.
- Exercise: Physical activity can shift circadian rhythms.
The suprachiasmatic nucleus (SCN) in the hypothalamus is the central biological clock that responds to zeitgebers, ensuring that internal rhythms align with external conditions.
Additional Information
Option (1) Have no effect on biological rhythms (Incorrect):
- Zeitgebers are essential for maintaining and regulating biological rhythms; they do affect them significantly.
Option (2) Sense biological rhythms (Incorrect):
- Zeitgebers do not "sense" rhythms but rather influence and reset them.
Option (4) Abolish biological rhythms (Incorrect):
- Zeitgebers do not abolish rhythms; rather, they help maintain synchronization. Even in the absence of external cues, the body maintains an intrinsic circadian rhythm.
