Our sleeping-waking cycle follows a(n) __________ rhythm.

A) infradian
B) circadian
C) diurnal
D) ultradian

Circadian Rhythm

The natural, internal process that regulates the sleep-wake cycle and repeats roughly every 24 hours.

Infradian

Referring to biological rhythms with cycles that are longer than a day, such as monthly cycles or seasonal behaviors.

Ultradian

Pertaining to recurrent periods or cycles repeated throughout a 24-hour day, such as cycles of sleep stages.