Biological rhythms in animals isolated from light and dark cues ________.
A) continue to have cycles of exactly 24 hours' duration
B) continue to have cycles of approximately 24 hours' duration; some more rapid, some slower
C) synchronize activity with whatever lighting cycle is imposed on them
D) cease having any rhythms

Question

Quizplus · Accepted Answer

Animals isolated from light and dark cues can still exhibit biological rhythms, but the duration of these cycles may vary from exactly 24 hours. Some may have faster rhythms, while others may have slower rhythms. This suggests that the internal biological clock of animals can still function without external cues.

Biological Rhythms in Animals Isolated from Light and Dark Cues