The sleep cycle is an example of a(n) ________ rhythm.

• A. circadian
• B. seasonal
• C. ultradian
• D. infradian

Answer: (A)

Verified step by step guidance

1. Understand that biological rhythms are natural cycles in physiological or behavioral processes that repeat over time.
2. Identify the types of biological rhythms based on their duration: circadian rhythms last about 24 hours, ultradian rhythms are shorter than 24 hours, infradian rhythms are longer than 24 hours, and seasonal rhythms occur over seasons.
3. Recognize that the sleep cycle typically follows a roughly 24-hour pattern, aligning with the day-night cycle.
4. Match the sleep cycle duration to the appropriate rhythm type, which is the one that repeats approximately every 24 hours.
5. Conclude that the sleep cycle is an example of a circadian rhythm because it follows this daily cycle.