In this task, you are given a question and an answer, you would be asked to create the sentence based on the Question-Answer provided. It should be contained within the Question-Answer provided.

Question: What occurs before the endometrium thickens in estrous cycles? Answer: ovulation
Ovulation occurs before the endometrium thickens in estrous cycles.

Question: What is the term for daily cycles of behavior, like the sleep-wake cycle? Answer: circadian rhythms
Circadian rhythms is the term for daily cycles of behavior, like the sleep-wake cycle.

Question: What is the layman's term for a state in which external stimuli are received but not consciously perceived? Answer: sleep

Sleep is the layman's term for a state in which external stimuli are received but not consciously perceived.